Exam Preparatory Manual for Undergraduates: Medicine Ramadas Nayak, Archith Boloor
INDEX
Page numbers followed by f and t indicate figure and table respectively.
β-Thalassemia intermedia 554
β-Thalassemia major 553
clinical features 553
investigations 554
management 554
β-Thalassemia minor 554
ϒ-Glutamyl transpeptidase (GGT) 740
A
Abdominal tuberculosis 722
gastrointestinal tuberculosis 722
etiology 722
pathology 722
peritoneal tuberculosis 722
solid organ tuberculosis 722
tuberculosis of mesenteric lymph nodes 722
ulcers in intestine 724
Acanthosis nigricans 1103
treatment 1104
Achalasia of the esophagus 700
cause 700
clinical features 701
investigations 701
management 701
endoscopic 701
surgical 701
Acid-base balance 821, 877
classification of acid-base disorders 877
maintenance of acid-base balance/PH 877
regulation of acid-base balance 877
Acromegaly 30
clinical features 30
etiology 30
investigations 31
treatment 31
Actinomycete infections 155
actinomyces israelii 156
nocardiosis 155
Actinomycosis 314
Active immunization 1086
Acute adrenal crisis 62
clinical features 62
management 62
Acute bronchopneumonia 315
clinical features 315
predisposing factors 315
treatment 315
Acute coronary syndrome 400, 403
clinical features 403
complications 404
Acute exacerbations of COPD 250
Acute HIV syndrome 203
Acute kidney injury 827
classification 827
clinical features 829
complications 830
etiopathogenesis 828
investigations 829
management 831
Acute liver failure 761
classification 761
fulminant hepatic failure 762
clinical features 762
complications 762
investigations 762
management 763
Acute mania 1020
Acute pyelonephritis 855
clinical features 855
investigations 855
management 856
Acute serum sickness 1080
clinical features 1080
treatment 1080
Acyanotic congenital heart diseases 490
Adams-stokes attacks 482
clinical features 482
etiology 482
treatment 482
Addison's disease 59, 105t
cardinal features 60
clinical features 60
investigations 61
management 61
Adrenal gland disorders 55
adrenocortical insufficiency 59
causes 59
classification 59
Cushing's syndrome 55
causes 55
clinical features 55
features 56
investigations 57
management 58
mnemonic for 56
hyperaldosteronism 58
primary hyperaldosteronism 58
secondary hyperaldosteronism 59
Nelson's syndrome 58
Adult immunization 1086
Adult-onset Still's disease 672
Adult T-cell lymphoma/leukemia 598
Adverse drug reaction 1125
classification 1125
type A 1125
type B 1125
type C 1125
management 1126
severity 1125
types 1125
A-fetoprotein 742
Agnosia 889
Albendazole 170
Alcoholic liver disease 803
alcoholic fatty liver 803
clinical features 803
investigations 804
alcoholic hepatitis 804
investigations 804
prognosis 804
treatment 804
Alcohol misuse and dependence 1035
Alcohol withdrawal 1038
clinical features 1038
Algid malaria 161
Allergy 1075
Alloimmunization 620
Alport's syndrome 839
Alzheimer's disease 957, 1091
clinical feature 957
diagnostic criteria 957
etiology 957
investigations 957
treatment 958
Amebic liver abscess 796
clinical features 796
complications 797
diagnosis 797
pathogenesis 796
treatment 797
Amikacin 196
Aminophylline 236
Ampulla of vater 738
Analgesic poisoning 993
Ancylostomiasis (hookworm) 173
clinical features 173
diagnoses 173
investigations 173
treatment 173
Anemia 530
classification 532
clinical features 533
signs 533
Anemia of chronic disease 561
causes 561
investigations 561
management 561
pathogenesis 561
Angelman syndrome 1057
Angel's trumpet 996
Angina pectoris 394
Angioedema 1076
C1-esterase inhibitor deficiency 1077
clinical features 1077
etiology 1076
treatment 1077
Anion gap 878
Ankylosing spondylitis 650
clinical features 650
diagnostic criteria 651
investigations 651
management 652
Anorexia 680
Anosognosia 889
Anthrax 112
clinical manifestations 112
cutaneous anthrax 112
gastrointestinal anthrax 112
inhalational anthrax 112
diagnosis 112
mode of transmission 112
treatment 112
Antiarrhythmic drugs 484
Anticholinergics 236
Anticholinergic toxidrome 996
Anti-infective therapy 193
antibiotic chemoprophylaxis 194
antimicrobial combination therapy 193
multidrug therapy 193
Antineutrophil cytoplasmic antibodies 636
Antinuclear antibodies 636
Antiphospholipid antibody syndrome 675
clinical features 676
diagnosis 676
management 677
types 676
Antituberculous chemotherapy 269
short-course chemotherapy 269
advantgaes 269
Antituberculous drugs 271
Antituberculous drugs 266
classification 266
Antiviral agents 197
Anuria 824
Anxiety disorders 1028
differential diagnosis 1029
types 1028
generalized anxiety disorder 1029
panic (paroxysmal) disorder 1028
phobic anxiety disorder 1028
post-traumatic stress disorder 1029
Aphasias 888
fluent aphasias 888
nonfluent aphasias 888
Apical impulse 390
abnormal apical impulse 390
normal apical impulse 390
cause 390
Aplastic anemia 561
causes 561
clinical features 561
investigations 562
Approach to renal diseases 822
azotemia 822
examination of the urine 823
glomerular filtration rate 822
renal function tests 823
ultrasonography 823
Apraxia 888
types 889
dressing apraxia 889
gait apraxia 889
gaze apraxia 889
ideational apraxia 889
ideomotor apraxia 889
Argyll Robertson pupil 965
Arterial pulses 370
examination 370
Arteriovenous fistula 859
Arteriovenous shunt 859
Arthralgia 203
Arthritis 634
inflammatory arthritis 634
aggravation 634
examination 634
laboratory investigations 634
pain and stiffness 634
noninflammatory arthritis 634
laboratory investigations 634
pain 634
stiffness 634
Asbestos-related lung and pleural diseases 325
Ascaris lumbricoides (roundworm) 172
clinical features 172
diagnoses 172
investigations 172
management 172
Ascites 782
clinical features 783
differential diagnosis 784
investigations 784
management 785
pathogenesis/mechanisms 782
Aspergilloma 353
Aspiration pneumonia 315
predisposing factors 315
Asthma COPD overlap syndrome 256
Ataxia 885, 935
gait ataxia 936
truncal ataxia 936
Ataxia-Telangiectasia syndrome 1072
Atelectasis 283
classification 283
nonobstructive atelectasis 284
obstructive atelectasis 283
clinical features 284
investigations 284
Atlantoaxial instability 1050
Atrial fibrillation 475
atrial flutter 478
clinical features 476
etiology 475
investigations 476
management 477
mechanisms 476
Atrial septal defect 492
Atrioventricular blocks 481
Atypical mycobacterial infections 207
clinical features 207
mode of infection 207
treatment 208
Atypical pneumonias 313
Austin Flint murmur 382t
Autoimmune hemolytic anemia 558
Autoimmune hepatitis 757
clinical features 757
course and prognosis 758
investigations 757
Autoimmunity 1080
mechanisms 1080
environmental factors 1081
genetic factors 1081
therapy of autoimmune disease 1081
Avian influenza 319
clinical features 319
investigations 319
prevention 319
treatment 319
Azoospermia 1050
B
Babinski Negolette syndrome 898t
Bacterial aspiration pneumonia 316
clinical features 316
diagnosis 316
treatment 316
Bacterial endocarditis prophylaxis 459
indications 459
Bacterial infections 107
streptococcal infections 107
cellulitis 108
erysipelas 108
lymphangitis 108
pneumonia and empyema 108
scarlet fever 107
streptococcal bacteremia 108
streptococcal myositis 108
streptococcal pharyngitis 107
streptococcal toxic shock syndrome 108
treatment 110
Bacterial peritonitis 786
acute bacterial peritonitis 786
investigations 787
signs 787
symptoms 787
treatment 787
chronic bacterial peritonitis 787
Baker's cysts 639
Barbiturate poisoning 992
Barrel-shaped chest 253
Bartter's criteria 871
Baseline HIV-antibody test 220
Basophils 565
BCG vaccination 278
advantages 278
complications 278
contraindications 278
procedure 278
Beckwith-Wiedemann syndrome 69t
Beevor's sign 947
Behçet's disease/syndrome 659
clinical features 660
treatment 660
Bell's palsy 969
clinical manifestations 969
investigation 969
pathophysiology 969
sequelae 970
treatment 970
Bence-Jones proteinuria 587t
Benedict's syndrome 898t
Benign tertiary (gummatous) syphilis 183
Berger's disease 838
Biguanides-metformin 80
Biliary cirrhosis 801
primary biliary cirrhosis 801
clinical features 801
complications 802
etiology and pathogenesis 801
investigations 801
secondary biliary cirrhosis 802
Bilirubin in the urine 741
Black death 113
Black measles 133
Bleeding disorders 602
evaluation/investigation 602
Blistering (bullous) disorders of skin 1107
bullous pemphigoid 1109
clinical features 1109
diagnosis 1109
etiopathogenesis 1109
treatment 1109
dermatitis herpetiformis 1109
differential diagnosis 1109
treatment 1109
types of blistering diseases 1107
Blood groups and diseases 620
Blue bloaters 254
Blumer's shelf 817
Boerhaave's syndrome 681
Bone marrow examination 630
Botulism 114
classification 114
food-borne botulism 114
infantile botulism 115
wound botulism 115
clinical features 115
food-borne botulism 115
infantile botulism 115
wound botulism 115
diagnosis 115
mode of infection 114
treatment 115
Bourneville disease 1117
Brain death 962
diagnosis 963
Brain natriuretic peptide 470
Brainstem reflexes 960
Breath sounds 363
bronchial breath sounds 363
vesicular breath sounds 363
Bronchial asthma 230
characteristics 230
classification 230
clinical features 232
chronic asthma 233
severe acute asthma 233
differential diagnosis 234
investigations 233
arterial blood gas analysis 234
blood and sputum tests 234
exhaled nitric oxide 234
imaging 234
lung function tests 233
measurement of allergic status 234
trial of corticosteroids 234
management 235
pathogenesis 231
risk factors and triggers 231
Bronchial thermoplasty 238
Bronchiectasis sicca 283
Bronchoalveolar lavage 263
Bronchodilators 235, 249
Brown-Séquard syndrome 949
Brown's syndrome 640
Brucellosis 123
clinical features 123
acute brucellosis 123
chronic brucellosis 123
subacute brucellosis 123
diagnosis 124
mode of infection 123
treatment 124
Brugada syndrome 481
Budd-Chiari syndrome 790
Buerger disease 660
clinical features 661
diagnosis 661
Bundle branch blocks 388
Burkitt lymphoma 161, 597
clinical features 597
investigations 598
management 598
Button-Hole' deformity 639
C
Cabot-Locke murmur 382t
Calcium pyrophosphate dihydrate deposition disease 670
clinical features 671
common causes 671
investigations 671
Cancer cell growth 1004
Cancers in HIV 211
Cancer treatment 1005
Caplan's syndrome 325
Carbamate poisoning 985
Carcinoid tumors 716
carcinoid syndrome 716
classification 716
clinical features 716
diagnosis 716
treatment 717
Cardiac arrest 505
Cardiac arrhythmias 472
main types 472
mechanism 472
Cardiac cirrhosis 802
cause 802
clinical features 802
diagnosis 803
mechanism 802
treatment 803
Cardiac creatine kinase 405
Cardiac sounds on auscultation 379
Cardiac tumors 527
Cardiogenic shock 404
Cardiovascular diseases 210
Cardiovascular syphilis 183
Carey coombs murmur 382t, 426
Carpal Tunnel syndrome 639, 928
Casoni's skin test 171
Castleman's disease 599
Catamenial pneumothorax 302
Catastrophic antiphospholipid syndrome 677
Cauda Equina syndrome 950
Causes of anemia in malaria 160
Causes of chronic diarrhea 690
Causes of diarrhea in the tropics 690
Causes of hemoptysis 355
Causes of hypercapnia 222
Causes of low back pain 679
Causes of macrocytosis 545
Causes of splenic rupture 633
Central nervous system infections 189
Central venous catheter 859
Cerebral hemispheres 889
Cerebral venous thrombosis 907
clinical features 907
diagnosis 907
pathophysiology 907
treatment 908
Cerebrospinal fluid 920
Cestodes (tapeworms) 169
Chandra-Khetarpal syndrome 280
Charcot's triad 748
Chediak Higashi syndrome 280
Chemical aspiration pneumonia 315
clinical features 315
treatment 316
Chest pain 365
common causes 365
Cheyne-Stokes breathing 366
causes 367
clinical presentation 367
conditions associated 366
investigations 368
management 368
mechanism 366
physical examination 368
Child-Pugh score 769
Chlamydial infections 181
lymphogranuloma venereum 181
clinical features 181
diagnosis 181
Chlamydia pneumonia 313
cause 313
chest radiographs 314
clinical presentation 314
mode of transmission 313
predisposing factor 314
Chloramphenicol 196
Cholera 124
clinical features 124
diagnosis 125
mode of transmission 124
pathogenesis 124
treatment 125
Chorea 943
causes 943
general features 943
signs 943
treatment 943
Chorea minor 427
Chromosomal disorders 1047
classification 1047
numerical chromosomal aberrations 1047
structural chromosomal aberration 1047
Chronic alcohol misuse 1036
Chronic blood and mucus in the stools 683
causes 683
investigations 683
Chronic hepatitis B 758
clinical features 759
investigations 759
phases 758
prognosis 760
Chronic hepatitis C 760
clinical features 760
investigations 760
Chronic hepatitis D 761
Chronic kidney disease 422t, 842
causes 842
clinical approach 842
history 842
symptoms 842
clinical features 843
complications 843
investigations 845
management 846
polycystic kidney diseases 848
types 848
urinalysis 845
hematology 846
immunology 846
radiological investigation 846
renal biopsy 846
serum biochemistry 846
Chronic lymphocytic leukemia 577
Chronic myeloid leukemia 573
clinical features 577
clinical staging 578
investigations 574, 577
molecular pathogenesis 573
natural course 574
peripheral smear 574
signs 574
symptoms 574
treatment 575, 578
types 577
Chronic myelopathies 949
Chronic obstructive pulmonary disease 244
chronic bronchitis 244
clinical features 246
complications 248
course and prognosis 248
etiology 245
investigations 247
management 248
pathogenesis 246
risk factor 245t
Chronic organophosphate poisoning 986
Chronic pyelonephritis 856
clinical features 856
investigations 856
management 857
types 856
Churg-Strauss syndrome 362
classic clinical features 658
investigations 659
treatment 659
Chylous pleural effusion (chylothorax) 297
causes 297
mechanism 297
pleural fluid findings 297
presentation 297
treatment 297
Cigarette smoking 255
chemical constituents of cigarette smoke 255
components of cigarette smoke 255
main stream smoke 255
side stream smoke 255
Ciliary dysfunction syndromes 284
Circle of Willis 979
Circulatory failure: shock 513
Cirrhosis 765
causes 765
classification 765
clinical features 766
investigations 770
hematological tests 770
imaging 770
liver function tests 770
Cisplatin 1008
Classic polyarteritis nodosa 657
clinical features 657
diagnosis 658
treatment 658
Claude's syndrome 898t
Clicking pneumothorax 302
Clubbing 223
causes 224
grades of clubbing 224
mechanisms 223
Cluster headache 893
clinical features 893
diagnostic criteria 893
management 894
pathophysiology 893
Coal Workers' pneumoconiosis 324
Coarctation of aorta 491
Coast of california 1118
Cogan syndrome 660
Cole-Cecil murmur 382t
Coma 958
approach to a patient with coma 959
classification 959
Combination antiretroviral therapy 212
Community-acquired pneumonia 305
clinical features 306
complications 307
investigations 306
management guidelines 308
types of presentations 306
Community setting or community acquired pneumonia 304
Complement system 1067
complement deficiencies 1068
complement system and disease 1067
pathways 1067
alternative pathway 1067
classical pathway 1067
lectin pathway 1067
Complete blood counts 220
Complete cord transection 945
Complications of blood transfusion 618
Comprehensive geriatric assessment 1098
aims 1098
interprofessional team interface 1098
Compressive myelopathies 946
Conduction system of the heart 382
Congenital heart diseases 490
Congenital nonhemolytic hyperbilirubinemias 746
Congenital rubella syndrome 134
Congenital syphilis 184
Congenital toxoplasmosis 168
Conjugated hyperbilirubinemia 738
Constipation 682
causes 682
investigations 682
treatment 683
Cooley's anemia 553
Coombs' test 619
Coronary artery disease 394
Cor pulmonale 508
clinical features 509
investigations 509
types 508
acute 508
chronic 508
Courvoisier's law 748, 816f
Coxiella burnetii 104
Creutzfeldt–Jakob disease 1090t
Crigler-Najjar syndrome 747
type I 747
etiology 747
features 747
treatment 747
type II 748
treatment 748
Crohn's disease 105, 729
clinical features 730
etiology and pathogenesis 729
investigations 730
pathology 729
treatment 731
Cruveilhier-Baumgarten murmur 382t
Cullen's sign 809
Curb 65
rule 308t
Cushing syndrome 817
Cutaneous larva migrans (creeping eruption) 173
clinical features 174
treatment 174
Cyanide poisoning 995
Cyanosis 225
causes 226
types 225
Cyanotic congenital heart diseases 496
Cyclothymic disorder 1021
Cystic diseases of kidney 847
Cysticercosis 169
Cystic fibrosis 280, 288
clinical features 288
gastrointestinal tract 289
respiratory tract 288
diagnosis 289
genetics and pathogenesis 288
treatment 289
Cytokines 1065
Cytomegalovirus 104
D
Dahl sign 253
Datura poisoning 996
Dawn phenomenon 94
Debakey classification 511
Defects in hemoglobin production 548
Dejerine-Roussy syndrome 898t
Delirium 1034
cardinal features 1034
causes of 1034
management 1035
Delusions and hallucinations 1018
Demyelinating diseases 908
multiple sclerosis 908
clinical manifestations 909
diagnosis 909
epidemiology 908
etiology and pathogenesis 908
pathophysiology 908
treatment 909
Depression 1093
De Quervain's thyroiditis 45
Diabetes insipidus 33
causes 33
complications 33
diagnosis 33
investigation 33
treatment 34
types 33
Diabetes mellitus 70
classification 70
type 1 diabetes 70
type 2 diabetes 70
clinical features 74
complications 88
acute 88
chronic 95
diagnosis 76
etiology 70
etiopathogenesis 71
management 78
pathogenesis of type 2 diabetes mellitus 72
Diabetic amyotrophy 99
Diabetic glomerular disease 825
Diabetic ketoacidosis 90t
Diabetic nephropathy 96
Diabetic neuropathy 98
Diabetic proximal neuropathy 99
Diagnosis of acute rheumatic fever 428
Diagnosis of HIV infection or AIDS 211
detection of virus specific antibodies 211
direct detection of viral material/infection 212
hematological abnormalities 212
Diarrhea 689
acute 689
cause 689
chronic 689
Diffuse parenchymal lung disease 320
clinical features 321
physical examination 321
etiology 321
investigations 321
treatment 322
Diffusing capacity of lung 229
DiGeorge syndrome 52
Digoxin 527
Diphtheria 110
clinical features 111
cutaneous 111
respiratory 111
complications 111
diagnosis 111
management 111
mode of transmission 110
pseudomembrane 110
Diplopia 967
Diseases of cranial nerves 964
abducens nerves 966
facial nerve 968
oculomotor 966
olfactory nerve 964
optic nerve 964
trigeminal nerve 968
trochlear 966
Diseases of immune dysregulation 1073
Diseases of kidney and genitourinary system 210
Diseases of the intestine 708
celiac disease 712
clinical features 713
complications 713
etiology 712
pathology 712
treatment 713
lactose intolerance 714
clinical features 714
etiology 714
investigations 714
treatment 714
malabsorption syndrome 708
classification 708
clinical features 708
etiology 708
investigations 710
tropical sprue 713
clinical features 713
diagnosis and investigations 714
etiology 713
treatment 714
Diseases of the myocardium 485
cardiomyopathy 486
classification 486
dilated (congestive) cardiomyopathy 487
treatment 488
myocarditis 485
clinical features 485
etiology 485
investigations 486
management 486
Diseases of the pericardium 498
acute pericarditis 498
classification 498
clinical features 498
etiology 498
investigations 499
treatment 499
cardiac tamponade 501
clinical features 501
investigations 501
management 501
chronic constrictive pericarditis 502
clinical features 502
etiology 502
investigations 502
treatment 503
pericardial effusion 500
clinical signs 500
investigations 500
signs 501
treatment 501
Diseases of the peripheral nervous system 927
mononeuropathies 928
mononeuropathy multiplex 928
polyneuropathies (peripheral neuropathy) 928
Diseases of the spinal cord 945
Diseases of vessels 510
aortic aneurysms 510
classification 510
aortic dissection 510
classification 511
clinical features 511
investigations 511
management 511
predisposing factors 510
Disorders of blood lipids and lipoproteins 522
Disorders of coagulation (clotting) 608
hemophilia 608
antenatal diagnosis 609
clinical features 608
laboratory investigations 609
management 609
mode of inheritance 608
hemophilia B 610
Disorders of phagocyte function 1073
Disorders of potassium balance 873
hyperkalemia 875
causes 876
clinical features 876
investigations 876
treatment 877
hypokalemia 874
causes 874
investigations 874
management 875
potassium 873
Disorders of skin appendages 1118
acne vulgaris 1118
clinical features 1118
management 1119
Disorders of sodium and water balance 865
composition of body fluids 865
electrolytes 865
Disorders of sodium balance 866
hyponatremia 867
clinical features 868
investigations 869
management 869
pathophysiology 867
osmotic demyelination syndrome 873
clinical features 873
risk factors 873
treatment 873
primary water depletion 872
causes 872
sodium (NA+) 866
syndrome of inappropriate antidiuretic hormone secretion 870
clinical features 871
etiology 871
treatment 871
Disseminated intravascular coagulation 613
clinical features 614
laboratory findings 615
management 615
pathogenesis 614
Dissociative (conversion) disorder 1023
Dock's sign 492
Dock's murmur 382t
Donath-Landsteiner test 560
Dots 270t
Down syndrome 1049
clinical features 1049
etiology 1049
pathogenesis 1049
Doxycycline 196
Drowning 1002
management 1003
pathophysiology 1002
signs 1003
symptoms 1003
Drug induced asthma 243
Drug interaction 1127
mechanism 1127
pharmacodynamic interaction 1128
prevention 1128
Drug resistance 194
Drug-resistant TB 271
Drugs used in hematological diseases 625
Drugs used in liver disorder 1128
Drugs use in kidney disorders 1128
Drugs use in pregnancy 1129
Drug therapy in chronic bronchitist 249
Dubin-Johnson syndrome 748
clinical features 748
etiology 748
investigations 748
Duckett Jones criteria 428
Dumping syndrome 707
early dumping 707
late phase of dumping 707
Dynamic auscultation 391
Dysarthrias 889
Dysentery 120
amebiasis 121
etiology 121
amebic colitis 121
amebic dysentery 121
non-dysenteric amebic colitis 122
bacillary dysentery 120
clinical features 120
complications 121
diagnosis 121
management 121
Dysmetabolic syndrome 102
Dysphagia 695
causes 695
differential diagnosis 695
investigations 696
Dyspnea 358
acute 359
bronchial obstruction 360
causes 358
management 361
mechanisms 368
Dyspnea differentiation index 229
Dyspnea with prolonged expiration 253
E
Eastern equine encephalitis 141t
Eating disorders 1044
anorexia nervosa 1044
clinical features 1045
course and outcome 1045
diagnostic tests 1045
etiology 1044
physical examination 1045
symptoms 1045
treatment 1045
bulimia nervosa 1045
etiology 1046
outcome 1046
physical examination 1046
symptoms 1046
treatment 1046
Ebstein anomaly 497
Ectopic beats 472
Eczema 1104
atopic dermatitis 1104
clinical features 1104
etiology 1104
management 1105
contact dermatitis 1106
allergic contact eczema 1106
irritant contact eczema 1106
treatment 1106
pityriasis versicolor 1107
seborrheic dermatitis 1106
clinical features 1106
etiology 1106
sites of involvement 1106
treatment 1107
treatment 1107
Edema 881
localized edema 883
nonpitting edema 882
causes 882
treatment 883
pitting dependent edema 881
causes 881
treatment 882
Eisenmenger's syndrome 495
Electrocardiogram 383, 405
ECG leads 384
sinus rhythm 383
Electroconvulsive therapy 1030
contraindications 1031
course 1031
indications 1030
procedure for modern ECT 1030
risks and side effects 1031
Emphysema 251
clinical features 252
complications 254
etiology 252
investigations 254
pathogenesis 252
treatment 254
types 252
centriacinar (centrilobular) emphysema 252
distal acinar (paraseptal) emphysema 252
irregular (scar or cicatricial) emphysema 252
panacinar (panlobular) emphysema 252
Empty sella syndrome 27, 69t
Empyema thoracis 297
clinical features 298
complications 298
etiology 298
investigations 298
management 299
Endocrine tumors of pancreas 818
alpha cell tumor 820
clinical features 820
treatment 820
beta cell tumor 818
clinical features 818
diagnosis 818
radiology 818
treatment 818
endocrine tumors 818
Endoscopic retrograde cholangiopancreatography 742
complications 742
procedure 742
Endoscopic ultrasound 743
Enteric fever 116
causative agent 116
clinical features 117
complications 117
laboratory diagnosis 117
pathogenesis 117
source of infection 116
treatment 118
Enterobius vermicularis (threadworm/pinworm) 171
Enteropathic arthritis 654
clinical features 654
treatment 654
Eosinophilia 565
Epigenetics 1061
Epilepsy syndromes 912
juvenile myoclonic epilepsy 912
Lennox-Gastaut syndrome 912
mesial temporal lobe epilepsy syndrome 913
Epstein-Barr virus 104
Erythrocyte sedimentation rate 1066
Erythropoietin 629
Esophageal varices 774
clinical features 774
diagnosis 774
management 774
Essential hypertension 414
clinical features 415
etiology 414
investigations 417
target organ damage 416
blood vessels 417
cardiovascular complications 416
central nervous system complications 416
renal complications 417
treatment 417
Ethambutol 267
Evaluation of gastrointestinal disease 680
Exacerbations of asthma 241
Exhaled nitric oxide 230
Extensive drug resistance TB 272
Extractable nuclear antibodies 636
Extramedullary spinal cord compression 948
Extra-pulmonary tuberculosis 273
F
Faine's criteria 131
Familial mediterranean fever 106
Fanconi's anemia 562
Fate of Ghon complex 258
Fatty liver 764
non-alcoholic fatty liver disease 764
classification 764
clinical features 764
diagnosis 764
investigations 764
management 764
risk factors 764
Febrile neutropenia 1011
Felty's syndrome 643
clinical features 644
laboratory findings 644
prognosis 644
treatment 644
Fibreoptic bronchoscopy 332
Fibrinolysis 611
Fibromyalgia syndrome 672
Filariasis 174
lymphatic filariasis 174
clinical features 175
diagnoses 175
investigations 175
treatment 175
Fitz-Hugh-Curits syndrome 179
Flaccid paraplegia 951
Fletcher's medium 131
Flexor spasms 947
Fluorescein angiography 98
Folate deficiency 542
Folic acid metabolism 539
Food poisoning 119, 691
causes 119
clinical feature 120
diagnosis 120
Forschheimer spots 134
Frailty syndrome 1093
Fresh frozen plasma 616
Friderichsen syndrome 64
Friedlander's pneumonia 312
Friedreich's ataxia 937
Froin's syndrome 927
Frontotemporal dementia 1091
Frozen red blood cells 617
Functional anatomy of kidney 821
juxtaglomerular apparatus 821
unit of kidney 821
Functions of liver 738
Fungal infections 151
candidiasis (moniliasis) 151
diagnosis 152
lesions/conditions 152
treatment 152
superficial mycoses 152
dermatophytes 153
favus 153
kerion 153
pityriasis versicolor 153
Fungal infections of lung 355
G
Gardner syndrome 736
Garland sign 954
Gastric outlet obstruction 708
causes 708
consequences 708
treatment 708
Gastroesophageal reflux disease 697
clinical features 698
investigations 699
pathophysiology 697
treatment 699
Gastrointestinal disease 208
diarrhea 208
esophageal diseases 208
treatment 208
Gastrointestinal infections 189
Gastrointestinal tuberculosis 274
Gaucher's disease 632t
Generalized abdominal distension 737
General measures in asthmatics 238
Gene therapy 1058
types 1058
germ cell therapy 1058
somatic cell therapy 1058
Genetic therapy 1058
Genital ulcer disease 186
Genome detection assays 212
Germline gene therapy 1058
Gestational diabetes mellitus 101
Ghon complex 258
Ghon lesion/focus 258
Giant cell arteritis 656
clinical features 656
investigation 657
Giardiasis 715
clinical features 715
treatment 716
Gilbert's syndrome 738, 747
clinical features 747
etiology 747
investigation 747
treatment 747
Glomerulonephritis 832
causes 832
hereditary nephritis 839
clinical presentation 839
treatment 839
IGA nephropathy 838
clinical features 839
diagnosis 839
management 839
prognosis 839
nephrotic syndrome 835
causes 836
investigations 837
management 837
pathophysiology 835
poststreptococcal (postinfectious) glomerulonephritis 832
clinical features 833
etiology and pathogenesis 833
investigations 833
management 833
rapidly progressive glomerulonephritis 834
classification 834
crescent 834
investigations 834
Glossitis 684
investigations/diagnosis 715
Glucose-6-phosphate dehydrogenase deficiency 554
clinical features 555
investigations 555
treatment 555
Glycosylated hemoglobin 87
Goals of cart 212
Goals of insulin therapy 83
Goiter 47
classification 47
clinical features 47
etiology 47
investigations 47
treatment 47
Gonadal disorders 65
male hypogonadism 65
androgen deficiency symptoms 65
gynecomastia 67
impotence 66
short stature 68
Goodpasture syndrome 835
Gottron's papules 678
Gout 668
clinical features 668
etiology 668
investigations 669
Graham Steell murmur 382t, 434
Gram's stain, Ziehl-Neelsen staining 287
Granuloma inguinale (donovanosis) 181
clinical features 182
diagnosis 182
Graves' disease 39
Grocco's sign 291
triangle 291
Growth hormone therapy 28
Guillain-Barré's syndrome 929
clinical features 930
etiology 930
immunopathogenesis 930
investigations/diagnosis 930
treatment 931
H
Hair disorders 1119
alopecia 1119
causes 1119
classification 1119
alopecia areata 1120
etiology 1120
stages 1120
treatment 1120
Hairy cell leukemia 573
clinical features 573
investigations 573
treatment 573
Hallmarks of cancer 1004
Hansen's disease 928
Hashimoto's thyroiditis 45t
Health care associated pneumonia 304
Heart failure 461
clinical manifestations 464
complications 466
framingham criteria for diagnosis of 465
investigations 466
management 467
pathophysiology 461
risk factors 464
signs 465
symptoms 464
types 462
Heart sounds 376
first heart sound 376
abnormalities 377
characteristics 377
intensity 377
mechanism 376
timing 376
fourth heart sound 379
causes 379
second heart sound 377
abnormalities 378
characteristics 377
third heart sound 378
causes 378
Heatstroke 998
Hematopoietic cell transplantation 621
allogenic bone marrow transplantation 623
autologous stem cell transplant 623
indications for hematopoietic stem cell transplantation 622
Hemiplegia 952
Hemoglobin structure 529
Hemolytic anemias 545
classification 546
clinical features 546
diagnosis 547
treatment 548
Hemolytic-uremic syndrome 613
clinical features 613
etiology and pathogenesis 613
investigations 613
treatment 613
Hemopoietic growth factors 629
Hemorrhagic pleural effusion 295
Hemostasis 600
components 600
mechanism 601
Henoch-Schönlein purpura 660
diagnostic criteria 660
investigations 660
treatment 660
Hepatic encephalopathy 777
clinical features 778, 793
etiology 777, 793
investigations 779, 793
pathogenesis 777
prevention 794
prognosis 794
types 778
Hepatic hydrothorax 769
Hepatic venous outflow obstruction 790
Hepatocellular carcinoma 793
Hepatopulmonary syndrome 769
Hepatorenal syndrome 781
clinical features 781
clinical types 781
diagnosis 781
investigations 781
pathogenesis 781
treatment 781
Hepatosplenomegaly 805
Hereditary cerebellar ataxia 937
clinical features 937
investigations 937
treatment 937
Hereditary spherocytosis 552
clinical features 552
investigations 552
treatment 552
Hering-Breuer reflex 368
Herniation syndromes 971
Hiatus hernia 697, 700
clinical features 700
investigations 700
management 700
types 700
Hiccough 682
causes 682
symptomatic treatment 682
Hide porter's disease 112
Highly active antiretroviral therapy 212
HIV genome 200
HIV infection 199
characteristic features 199
classification 203
etiology 199
properties 199
structure 200
HIV clinical staging 203
infection of cells by HIV 202
life cycle of HIV 202
modes/routes of transmission 201
parenteral transmission 201
perinatal transmission 201
sexual transmission 201
pathogenesis 201
major targets 201
HIV vaccine 220
Hodgkin lymphoma 592
classification 592
clinical manifestations 592
etiology 592
investigations 593
management 594
Hoover's sign 253
Hormones of anterior pituitary 25
Horner's syndrome 335, 966
Hospital-acquired pneumonia 316
clinical features 317
criteria 316
etiology 316
investigations 317
management 317
Huges syndrome 675
Human genome project 1060
ethical issues 1061
goals 1060
uses 1061
Huntington's disease 1090
Huntington's disease/chorea 943
etiology 944
manifestations 944
treatment 944
Hutchinson's incisors 184
Hydatid disease 170
Hyperbaric oxygen therapy 344
Hypercapnic encephalopathy 222
Hyperglycemic hyperosmolar state 91
Hyperlipidemia 524
Hypersensitivity pneumonitis 242
clinical features 243
complications 243
investigations 243
pathogenesis 242
treatment 243
Hypersensitivity reactions 1074
Hypersplenism 633
Hypertension 413
causes 413
classification 413
Hypertensive encephalopathy 422t
Hyperthyroid crisis 40
causes 40
clinical features 40
treatment 40
Hypopituitarism 25
clinical features 26
etiology 25
laboratory investigations 26
Hypothermia 1001
Hypothyroidism 41
classification 41
clinical features 41
clinical signs 42
etiology 41
Hashimoto's thyroiditis 41
postpartum thyroiditis 41
treatment 43
Hypotonia 884
Hypoxemia 223
clinical features 223
investigations 223
treatment 223
I
Idiopathic dermatomyositis 678
Idiopathic interstitial pneumonia 208, 322
Idiopathic polymyositis 678
Idiopathic pulmonary fibrosis 323
clinical features 323
investigations 323
treatment 323
Immune reconstitution inflammatory syndrome 218
Immune recovery following HAART 216
Immune response 1063
Immune system 1063
duality 1063
cell mediated immunity 1063
humoral (antibody-mediated) immunity 1063
Immune thrombocytopenic purpura 605
clinical features 605
diagnosis 606
investigations 606
pathogenesis 605
treatment 606
Immunization 1086
Immunodeficiency 1070
primary immunodeficiency diseases 1070
classification 1070
warning signs 1070
Immunoglobulins 617, 1064
antibody structure 1064
functions 1064
immunoglobulin 1064
features 1064t
Immunomodulators 1083
immunostimulants 1085
Bacillus Calmette-Guerin 1085
interferons 1085
levamisole 1085
thalidomide 1085
immunosuppressants 1083
antiproliferative/antimetabolic agents 1084
calcineurin inhibitors 1083
plasmapheresis 1086
Impulse disorders 1030
Incontinence 1094
categories of 1094
reversible conditions associated with urinary incontinence 1094
treatment options 1095
urinary incontinence 1094
Indian tick typhus 132
Indications for splenectomy 632
Indications of bronchoscopy 364t
Infective endocarditis 453
classification 453
clinical features 456
common organisms 454
complications 457
investigations 456
management 458
pathogenesis 455
predisposing factors 454
Inflammatory bowel disease 724, 733
complications 733
local complications 733
etiology and pathogenesis 724
environmental factors 724
genetic factors 724
host factors 725
Inflammatory muscle diseases 678
Influenza 317
etiology 317
influenza A virus 317
clinical features 318
complications 318
investigations 318
management 318
prevention 318
Ingested poison 980
Inheritance 1053
autosomal dominant pattern of inheritance 1053
autosomal recessive pattern of inheritance 1054
digenic inheritance 1057
mitochondrial inheritance 1057
X-linked pattern of inheritance 1055
X-linked dominant conditions 1055
X-linked recessive traits 1055
Y-linked diseases 1056
Insecticide poisoning 983
Insulin resistance 214
syndrome 102
Integrase inhibitors 214
Interferons 1066
Intestinal tuberculosis 274
Intracranial pressure 971
Intravenous gamma globulin 197
Invasive pulmonary aspergillosis 354
Investigations in oncology 1012
Iron deficiency anemia 534
clinical features 535
diagnosis 535
etiology 534
management 536
Irritable bowel syndrome 718
clinical features 719
investigations 720
pathophysiology 719
treatment 720
Ischemic colitis 717
clinical features 717
etiology 717
laboratory findings/investigation 717
treatment 717
Ischemic heart disease 392, 400
Ischemic stroke 896
etiology of ischemic stroke 896
investigations/diagnosis 899
pathophysiology 896
risk factors 897
symptoms 897
treatment 900
J
Japanese encephalitis 141t
Jarisch-Herxheimer reaction 185
Jaundice 744
classification 744
cholestatic jaundice 746
hemolytic jaundice 744
hepatocellular jaundice 745
Jugular venous pressure 373
Juvenile rheumatoid arthritis 69t
Juxtaglomerular apparatus 821
Juxtaglomerular cells 822
K
Kallman syndrome 27
Kaposi sarcoma 210
Kartagener's syndrome 280
Kayser-Fleischer ring 799
Kearns-Sayre syndrome 1057
Kerley's A line 435
Kerley's B line 435
Kerley's C line 435
Ketoconazole 197
Ketone bodies 89
Key-Hodgkin murmur 382t
Kimmelstiel-Wilson lesions 96
Klebsiella pneumonia 312
investigations 312
treatment 313
Klinefelter's syndrome 1050
clinical features 1050, 1051
diagnosis 1051
karyotypic abnormalities 1051
management 1051
pathogenesis 1050
Koch's disease 257
Koebner phenomenon 1101
Koplik spots 133
Kussmaul's sign 376
Kveim-Siltzbach test 351
L
Lamber-Eaton syndrome 331
Large-volume diarrhea 820
Laron's dwarfism 69t
Laryngeal swabs 263
Late latent syphilis 183
Laurence-moon and Bardet-Biedl syndromes 68t
Legionella pneumonia 314
clinical features 314
investigations 314
treatment 314
Legionnaire's disease 314
Leg ulcers 1120
Leishmaniasis 165
clinical syndromes 165
post-kala-azar dermal leishmaniasis 167
visceral leishmaniasis 165
treatment 167
Leprosy 125
bacteriological considerations 125
classification 125
clinical features 126
borderline leprosy 127
lepromatous leprosy 126
tuberculoid leprosy 126
diagnosis 128
mode of transmission 125
treatment 128
Leptospirosis 129
clinical features 129
etiology 129
mode of transmission 129
pathogenesis 129
source of infection 129
Leukemia 566
classification 566
clinical features 568
etiology 567
investigations 568
management 569
risk factors 567
Leukemoid reaction 572
Leukocytosis 564
Leukopenia 564
Lewy body disease 1090t
Lhermitte's sign or barber's chair syndrome 951
Libman-Sacks endocarditis 460
Lice infection 177
body lice 178
head lice (pediculosis capitis) 177
pubic lice 178
Lichen planus 1102
clinical features 1103
complications 1103
diagnosis 1103
etiology 1103
management 1103
prognosis 1103
Life cycle of pneumocystis jiroveci 206
Ligase chain reaction 273
Light's criteria 293
Lipodystrophy 526
Lipoproteins 522
Lithium 196
Liver biopsy 743
complications 744
contraindications 743
indications 743
Liver function tests 738
Liver transplantation 794
Locus heterogeneity 1058
Loeffler's syndrome 361
Loop of Henle 821
Lowenstein Jensen culture 273
Lower GI bleed 689
Lower motor neurons 884
Lugol's iodine 41
Lumbar puncture 920
Lung abscess 285
classification 285
clinical features 287
acute 287
chronic 287
complications 287
etiology 285
investigations 287
pathogenesis 286
treatment 287
Lung cancer 327
clinical features 329
etiology 328
incidence 328
lung cancer in india 329
pathology 329
Lung parenchyma 363
Lung volume reduction surgery 250
Lyell's syndrome 1111
Lymphadenopathy 203
Lymph node TB 274
Lymphocytosis 565
Lymphoid follicles 117
M
Macrocytic anemia 538, 541, 545
megaloblastic 545
nonmegaloblastic 545
role of vitamin B12 538
vitamin B12 metabolism 538
Magnetic resonance cholangiopancreatography 743
Major histocompatibility complex 1068
significance 1069
Maladie de Roger 494
Malignant ascites 789
causes 789
investigations 789
Malignant hyperthermia 104
Malignant pleural effusion 295
Malignant pustule 112
Mallory-Weiss syndrome 681
Malta fever 123
Management of acute attack of gout 670
Management of a patient with HIV infection 212
Management of chronic asthma 239
Management of HIV/AIDS during pregnancy 218
Manic episode 1021
Mantoux test 107t
Marfan's syndrome 69t, 512
Marie-Foix syndrome 898t
Marjolin's ulcers 1114
Martel sign 670
McCune-Albright syndrome 1118
Mediastinum 336
clinical features 337
compartments 337
investigations 337
management 338
Medications in psychiatry 1031
antidepressant medications 1032
adverse effects 1032
indications 1032
mechanisms of action 1032
antipsychotic medications 1031
general adverse effects 1032
indications 1032
anxiolytic medications 1033
mood-stabilizing medications 1033
Mediterranean fever 123
Megaloblastic anemia 539
etiology 540
manifestations 539
pathogenesis 540
Meigs' syndrome 789
Melioidosis 131
clinical features 131
diagnosis 131
treatment 132
Mendelson's syndrome 315
Ménière's disease 681
Meningitis 918
Meningitis and encephalitis 921
Mental retardation 1052
assessment of degree of mental retardation 1052
mild retardation 1052
moderate retardation 1052
severe retardation 1052
causes 1052
diagnostic tests 1053
treatment 1053
Mental state examination 1017
Mesenteric lymph node 117
Mesothelioma 326
Metabolic acidosis 879
Metabolic alkalosis 879
Metabolic liver disease 798
Metabolic syndrome 102
Methemoglobinemia 558
Methylxanthines 236
Microscopic agglutination test 131
Microscopic polyangiitis 658
clinical features 658
diagnosis 658
Middle east respiratory syndrome 320
clinical features 320
source of infection 320
treatment 320
Middle lobe bronchiectasis 284
Migraine 890
classification 890
clinical features 891
management 892
migraine with aura 891
migraine without aura 891
pathogenesis 891
Miliary or disseminated TB 275
classical (acute) miliary tuberculosis 275
complications 276
investigations 275
prognosis 276
signs 275
cryptic miliary tuberculosis 276
diagnosis 276
investigations 276
management 276
signs 276
symptoms 276
route of spread 275
Millard-Gubler syndrome 898t
Mill wheel murmur 382t
Mini-mental state examination 1092
Mixoploidy 1048
Modified measles 133
Mohs' micrographic surgery 1114
Mollaret's meningitis 926
Mood disorders 1018
bipolar disorder 1021
unipolar disorder 1019
Motor neuron disease 953
Movement disorders 937
types of movements 937
akathisia 937
asterixis 937
athetosis 937
ballismus 937
chorea 937
dyskinesia 937
dystonia 937
Mucocutaneous diseases 208
Mucormycosis 154
clinical categories 154
definitive diagnosis 154
impaired immune 154
treatment 154
Multidrug resistant TB 272
Munchausen's syndrome 1024
Murmurs 380
continuous murmurs 381
diastolic murmurs 381
innocent murmurs 382
systolic-diastolic murmur 381
systolic murmurs 380
Muscular dystrophies 934
Becker muscular dystrophy 935
Duchenne muscular dystrophy 934
endocrine myopathies 935
limb-girdle muscular dystrophy 935
myotonic dystrophy 935
Myalgias 203
Myasthenia gravis 931
clinical features 932
diagnosis 932
pathogenesis 931
pathophysiology 931
treatment 933
Myasthenic crisis 933
Mycetoma 155
clinical features 155
diagnoses/investigations 155
etiology 155
management 155
Mycobacteria 256
characteristics 257
classification 256
atypical mycobacteria 256
mycobacterium tuberculosis complex 256
determinants of virulence 257
epidemiology 257
mode of transmission 258
Mycobacteria growth indicator tube 273
Mycoplasma pneumonia 313
clinical presentation 313
complications 313
lab findings and diagnosis 313
treatment 313
Mycosis fungoides 599
Myelodysplastic syndromes 584
clinical features 585
diagnosis 585
etiology 584
treatment 586
WHO (2016) classification 585
Myelophthisis 584
Myeloproliferative neoplasms 579
Myocardial infarction 405
Myotonia 885
Myxedema coma 43
lab findings 43
management 44
precipitating factors 43
warning signs 43
N
Napier's aldehyde 167
Natural history of HIV infection 203
early acute phase 203
final crisis phase 205
middle chronic phase 204
Neck stiffness 926
Nephrolithiasis 849
clinical features 853
clinical manifestations 850
clinical presentation 852
diagnosis/investigations 850
etiology 849, 852
investigations 854
pathogenesis 853
treatment 851, 854
types 849
Neurocysticercosis 170
Neuroleptic malignant syndrome 104
Neurological manifestations of AIDS 209
bacterial infections 209
fungal infections 209
protozoan infections 210
viral infections 209
Neurophysiological testing 976
Neurosyphilis 919
Neutropenia and agranulocytosis 564
Neutrophilia 564
New Delhi metallolactamase 195
Newer antituberculous drugs 268
Nikolsky's sign 1108
Nonarticular rheumatism 672
Noncirrhotic portal fibrosis 803
clinical features 803
etiology 803
investigations 803
treatment 803
Nongastric diseases 703
Non-Hodgkin lymphoma 594
classification 595
clinical features 595
clinical staging 596
etiology 594
investigations 596
management 596
pathology 595
Non-IGE mediated anaphylaxis 1080
Noninfective endocarditis 460
Noninfective pneumonias 304
Non-nucleoside reverse transcriptase inhibitors 213
Non-ST-elevation myocardial infarction 403
Non-ST-segment-elevation acute coronary syndrome 411
Noonan's syndrome 68t
Normal arterial blood gas levels 222
Normocytic normochromic anemia 556
Nosocomial infection 189
classification 186
factors predisposing to hospital infection 187
health care-associated infection 186
mechanisms of transmission 187
Nosocomial infections 186
Nosocomial pneumonia or hospital acquired pneumonia 304
Nucleotide analogues 213
Nystagmus 967
O
Obsessive-compulsive disorder 1029
management 1030
types 1030
Occupational asthma 242
etiology 242
management 242
Occupational lung diseases 323
Ocular coherence tomography 98
Ocular diseases 210
Odynophagia 696
causes 696
Oliguria 824
Omenn syndrome 1072
Ondine's curse 343
Opioid agonists 997
Opportunistic mycoses 153
clinical syndromes 154
etiology 154
Oral glucose tolerance test 78
Oral hypoglycemic drugs 79
Oral ulceration 737
Organic brain syndrome 956
Organochlorine poisoning 987
Ortner's syndrome 437
Osteoarthritis 662
clinical manifestations 663
etiology 662
prevention 663
types 662
Osteoporosis 673, 674
classification 673
clinical features 673
epidemiology 673
pathogenesis 673
prevention 674
treatment 674
Oxygen therapy 344
P
Painful hepatomegaly 804
Painless obstructive jaundice 815
Palmar erythema 768
Palpitations 367
Pancoast's syndrome 335
Pancreatic cancer 816
clinical features 816
etiology 816
pathogenesis 816
pathology 816
Pancreatic cholera 820
Pancreatic transplantation 87
Pancreatitis 807
acute pancreatitis 807
classification 807
clinical features 808
complications 811
differential diagnosis 811
etiology 807
laboratory investigations 809
management 812
pathogenesis 808
chronic pancreatitis 812
clinical features 813
complications 814
etiology 813
investigations 813
treatment 814
investigations 817
prognosis 817
treatment 817
tropical pancreatitis 814
clinical features 815
etiology 814
investigations 815
treatment 815
Panniculitis 1123
erythema nodosum 1123
clinical features 1123
etiology 1123
treatment 1123
Paraneoplastic syndromes 330, 1014
Paraplegia 950
Parapneumonic effusion 296
categories 296
clinical presentation 296
investigations 296
treatment 296
Parasitic thyroiditis 45t
Parathyroid disorders 48
calcium homeostasis 48
distribution of calcium 48
hormonal regulators 48
importance of ionized calcium 48
regulation of calcium levels 48
hypercalcemia 50
causes 51
clinical features 51
management 51
hyperparathyroidism 49
causes 49
classification 49
clinical features 49
investigations 50
hypoparathyroidism 51
causes 51
pseudohypoparathyroidism 53
tetany 52
causes 52
clinical features 52
treatment 52
Parkinson's disease 938, 1090t
idiopathic 939
clinical manifestations 939
differential diagnosis 940
etiology 939
investigation/diagnosis 940
pathological features 939
treatment 941
Paroxysmal nocturnal dyspnea 369
Paroxysmal nocturnal hemoglobinuria 557
clinical features 557
diagnosis 557
etiology and pathogenesis 557
treatment 558
Pathogenesis of atherosclerosis 393
Pathogenicity of the virus 200
Patterns of HIV progression 205
long term nonprogressors 205
rapid progressors 205
slow progressors 205
typical progressors 205
Patterns of spinal cord disease 945
Patterson-Brown-Kelly syndrome 696
Pautrier microabscess 1116
Peak expiratory flow rate 228
Pel-Ebstein fever 593
Peptic ulcer disease 701
clinical features 703
complications 704
etiology 701
investigations/diagnosis 704
pathogenesis 702
treatment 705
Percutaneous transhepatic cholangiography 742
procedure 742
uses 743
Perianal itching (pruritus ani) 171
Pericardial friction rub 379
Pernicious anemia 541
etiology 541
Peutz-Jeghers syndrome 736
Peyer's patches 117
Phakomatoses 1116
café-au-lait macules 1118
neurocutaneous syndromes 1116
neurofibromatosis type 2 1117
tuberous sclerosis 1117
Pharmacogenetics 1125
Pheochromocytoma 64
clinical features 64
investigations 65
management 65
Philadelphia chromosome 575
Pick's disease 1091
Pickwickian syndrome 342
Pigmentary disorders of skin 1111
conditions associated with increased pigmentation 1113
hypopigmentation 1111
causes 1111
inherited hypopigmentation disorders 1113
pityriasis alba 1112
clinical features 1112
vitiligo 1111
classification 1111
clinical features 1111
management 1112
Pink puffers 254
Pituitary apoplexy 28
clinical features 28
management 28
Pituitary hormones 25
anterior 25t
posterior 25t
Pituitary tumors 28
classification 29
clinical features 29
investigations 29
treatment 30
Plague 113
clinical features 113
bubonic plague 113
cutaneous plague 114
pneumonic plague 113
septicemic plague 113
diagnoses 114
investigations 114
route of infection 113
source of infection 113
treatment 114
Plasma bicarbonate 92
Plasma cell leukemia 591
Plasma cell neoplasms 586
multiple myeloma 586
clinical features 586
diagnosis 587
investigations 588
staging 588
treatment 589
solitary extraosseous plasmacytoma 591
solitary plasmacytoma 590
Plasma glucose 92
Plasmapheresis 931
Pleiotropy 1057
Pleural effusion 289
causes 290
classification 290
clinical features 290
diagnosis 292
investigations 291
management 294
Pleural effusions in HIV infection 297
Pleural fluid analysis 292
Plummer-Vinson syndrome 696
Pneumococcal infections 110
meningococcal infections 110
meningococcal meningitis 110
Pneumococcal pneumonia 310
characteristic features 312
clinical features 311
complications 311, 312
etiology 310
investigations 311
blood 311
chest radiograph 311
serological tests 311
sputum 311
predisposing factors 312
treatment 311, 312
Pneumocystis pneumonia 206
Pneumonia 303
classification 303
primary pneumonia 303, 304
suppurative pneumonia 304
Pneumonia in immunocompromised host 304
Pneumothorax 299
classification 299
clinical features 300
complications 302
etiology 299
spontaneous pneumothorax 299
traumatic pneumothorax 300
investigations 300
treatment 302
types of spontaneous pneumothorax 300
closed spontaneous pneumothorax 300
open spontaneous pneumothorax 301
tension (valvular) pneumothorax 301
Poems syndrome 587
Poisonous snakes 987
Polyarthritis 679
Polycythemia vera 580
clinical course 581
clinical features 580
complications 581
diagnosis 581
etiology 580
Polymerase chain reaction 198
Polymorphisms 1058
Polymyalgia rheumatic 657
criteria for the diagnosis 657
treatment 657
Polyuria 824
Poncet's polyarthritis 262t
Pontain's murmur 375
Portal hypertension 771
classification 771
clinical features 772
complications 774
investigations 773
pathogenesis 772
Positron emission tomography 332
in oncology 1015
Postprimary (secondary) tuberculosis 259
clinical features 261
fate of secondary tuberculosis 260
morphology 260
source of infection 260
symptoms 261
Poststreptococcal glomerulonephritis 107
Post-tussive crepitations 262
Prader-Willi syndrome 68t, 1057
Prebiotics 735
Pre-exposure prophylaxis 220
Prerenal azotemia 92
Pretibial myxedema 39
Prevention of genetic disease 1062
Primary bronchial tumors 327
Primary myelofibrosis 582
clinical features 582
investigations 583
prognosis 583
treatment 583
Primary tuberculosis 258
primary tuberculosis of lung 258
sites of primary tuberculosis 258
Prinzmetal's variant angina 412
clinical features 412
etiology 412
investigation 413
management 413
prognosis 413
Probiotics 735
nature 735
preparation 735
uses 735
Prodromal dementia 1090
Progressive dyspnea 206
Prolactinoma 32
causes 32
clinical features 32
investigations 32
treatment 33
Protease inhibitors 214
Proteome 1061
Protozoal infections 156
malaria 156
clinical features 158
complications 159
management/treatment 162
Pruritus 1121
causes 1122
Pseudobronchiectasis 283
Pseudochylothorax 297
Pseudoclubbing 224
Pseudomembranous colitis 717
clinical features 718
investigations and diagnosis 718
treatment 718
Psoriasis 1100
associated features 1101
clinical features 1101
diagnosis 1101
etiology 1100
investigations 1101
management 1101
pathogenesis 1100
pathology 1101
types 1101
Guttate psoriasis 1101
plaque psoriasis 1101
Psoriatic arthritis 653
clinical features 653
diagnosis 653
management 654
types 653
Psychiatric disease 210
Psychosomatic disorder 1046
Psychosomatic disorders of the gastrointestinal tract 718
classification 718
Psychotic disorders 1024
Ptosis 966
Puddle sign 782
Puerperal disorders 1046
Pulmonary edema 470
causes 470
classification 470
investigations 471
Pulmonary embolism 517
Pulmonary eosinophilic syndromes 361
Pulmonary fibrosis 326
types 326
focal fibrosis 326
interstitial fibrosis 326
replacement fibrosis 326
Pulmonary function test 226
Pulmonary hypertension 503
clinical features 503
investigations 504
treatment 504
WHO classifications of 503
Pulmonary tuberculosis 261
causes of hemoptysis in pulmonary tuberculosis 264
complications 261t
investigations 262
blood examination 262
culture of sputum 263
radiological examination 262
sputum examination 263
radiological features of pulmonary tuberculosis 264
Pulsatile liver 804
Pyogenic abscess 795
clinical features 795
etiology 795
investigations 796
management 796
pathology 795
Pyrexia (fever) of unknown origin 103
clinical approach 105
history taking 105
physical examination 106
etiology 103
collagen vascular disease 104
infections 103
miscellaneous 105
neoplasms 104
periodic fevers 105
psychogenic fevers 104
undiagnosed 105
investigations 106
treatment 107
Q
Q fever 132
QRS-complex 387
QS wave 383
QT-interval 388
Quadriceps muscles of the lower limbs 99
Quadriplegia 952
Qualitative platelet defects 605
Qualitative test 229
Quantitative test 229
Quaternary syphilis 183
Quatran malarial nephropathy 161
Queckenstedt's test 927
Quinolones 196
Quinupristin-dalfopristin 110t
Q wave 383
Q
Radiometric methods 273
Ramsay-Hunt syndrome 139
Ranson scoring system 810
Rasmussen's aneurysm 264
Raymond-Cestan syndrome 898t
Raynaud's disease 512
Raynaud's phenomenon 512, 664
causes 512
classification and causes 513
clinical features 512, 514
investigations 513
management 515
pathogenesis 514
stages 514
treatment 513
types 515
RBC abnormalities 530
Reactive arthritis 652
clinical features 652
etiology 652
investigations 652
management 653
Reactive disorders of skin 1110
erythema multiforme 1110
causes 1110
classification 1110
clinical features 1110
pathogenesis 1110
Stevens-Johnson syndrome 1110
clinical features 1110
toxic epidermal necrolysis 1111
management 1111
Reaven syndrome 102
Recurrent spontaneous pneumothorax 301
Red blood cells 827
Red cell indices 529
Re-expansion pulmonary edema 294
Reflexes 885
Refractory heart failure 470
Reitan's number connection test 779
Reiter syndrome 106t
Relapsing polychondritis 671
Renal and hepatic function 220
Renal biopsy 863
complications 864
contraindications 864
indications 864
Renal calculus 840
Renal replacement therapies 858
acute dialysis in critically ill patients 860
hemodialysis 859
access for hemodialysis 859
basic principles 859
complications 859
peritoneal dialysis 860
complications 861
procedure 860
renal transplantation 861
advantages 861
complications 862
contraindications 862
immunosuppressive therapy 862
technique 862
treatment 863
Renal tubular acidosis (RTA) 840
mechanism 840
types 840
Respiratory acidosis 880
Respiratory alkalosis 880
Respiratory failure 338
acute type I and chronic type I
acute type II and chronic type II
classification 339
mechanisms 339t
Respiratory (pulmonary) function tests 226
Respiratory system 205
acute bronchitis and sinusitis 205
pneumocystis jiroveci infection 206
pneumonia 206
pulmonary tuberculosis 206
Reticulocyte 529
Retinopathy 210
Reye's syndrome 763
Rheumatic chorea 430
clinical features 430
etiology 430
management 430
prognosis 430
Rheumatic fever 107
Rheumatic heart disease 424
clinical manifestations 425
etiology 425
pathogenesis 425
Rheumatoid arthritis 637
clinical features 637
diagnosis 641
etiology 637
investigations 641
laboratory findings 638
management 642
general measures 642
medical therapy 642
symptoms 638
Rheumatoid factor 634
significance 634
Rheumatoid hand 638
Rheumatoid nodules 639
Rheumatoid vasculitis 639
Rickettsial diseases 132
treatment 132
Riedel's thyroiditis 45, 47t
Right ventricular hypertrophy 389
Rock fever of Gibraltar 123
Roger's murmur 382t
Role of folic acid 539
Role of steroid therapy 62
Romberg's test 936
Romhilt-Estes point score system 389
Roth's spot 106t
Rotor syndrome 748
investigations 748
Rubella syndrome 134
Russell-Silver dwarfism 69t
R wave 383
Rytand's murmur 382t
S
Salmonella osteomyelitis 117
Sarcoidosis 349
clinical features 349
etiology 349
investigations 350
noncaseating granulomas 349
Scabies 176
clinical features 176
crusted or norwegian scabies 176
diagnosis 176
mode of transmission 176
treatment 177
Schilling test 543
Schizoaffective disorder 1028
Schizophrenia 1025
etiology 1025
management 1027
physical and psychiatric presenting symptoms 1025
types 1026
Scorpion bite 990
signs and symptoms 990
treatment 991
Second line antituberculous drugs 268
capreomycin 268
cycloserine 268
ethionamide 268
fluoroquinolones 268
kanamycin and amikacin 268
macrolides 268
Secretory versus osmotic diarrhea 690
Sedative drug poisoning 991
Seizures 910
classification 910
absence seizures 911
atonic seizures 912
focal seizures 911
generalized seizures 911
myoclonic seizures 912
Sepsis 190
etiology 190
management 191
risk factors 191t
Seronegative arthritis 655
Serum osmolarity 92
Severe acute asthma 240
Severe acute respiratory syndrome (SARS) 319
clinical features 319
diagnosis 320
etiology 319
laboratory findings 319
treatment 320
Severe dengue 144
Sexually transmitted infections 178
chancroid 180
clinical features 180
diagnosis 181
gonorrhea 178
clinical features 179
diagnosis 179
treatment 179
nongonococcal urethritis 180
diagnosis 180
etiology 180
treatment 180
Sheehan's syndrome 27
clinical features 27
diagnosis 27
mechanism 27
treatment 27
Shy-Drager syndrome 683
Sickle cell anemia 69t
Sickle cell disease 117, 549
clinical features 549
in adults 550
in children 549
etiology 549
investigations 550
long-term complications 550
management 551
pathogenesis 549
Sick-sinus syndrome 479
clinical features 479
treatment 479
Sideroblastic anemias 556
Silicosis 326
accelerated silicosis 326
acute silicosis 326
chronic silicosis 326
Simple coal-worker's pneumoconiosis 324
Sinus arrhythmia 472
Sister Mary Joseph's node 817
Sjögren's syndrome 635,667, 815
classification 667
clinical features 667
laboratory investigations 667
Skin tumors 1113
basal cell carcinoma 1114
clinical presentation 1114
malignant melanoma 1115
classification 1115
clinical features 1115
etiology 1115
management 1116
pathogenesis 1115
malignant skin tumors 1113
categories 1114
etiology 1114
pathogenesis 1114
mycosis fungoides 1116
clinical features 1116
squamous cell carcinoma 1114
clinical features 1115
management 1115
risk factors 1114
Sleep apnea/hypopnea syndrome 341
central sleep apnea 343
causes 343
mechanisms 343
treatment 343
obstructive sleep apnea 342
clinical features 342
diagnosis 342
physical examination 342
treatment 343
Sleep disorders 1041
circadian rhythm sleep disorders 1043
diagnosis 1043
insomnia 1041
classification 1041
consequences 1041, 1042
narcolepsy 1042
clinical features 1042
diagnosis 1042
etiology 1042
treatment 1042
parasomnias 1043
features 1043
treatment 1044
types 1043
sleep-related movement disorders 1044
Snakebite 987
Snake venom 987
Solitary pulmonary nodule 338
Somatoform disorders 1023
Somatostatinoma 820
Somogyi phenomenon 94
Sphincter of Oddi 812
Spider naevi 767
Spinal cord 945
Spinal cord compression 948
Spinal pain 951
Spleen 631
Splenic abscess 123
Splenomegaly 631, 805
Square root sign 376
Stable angina pectoris 394
Staphylococcal pneumonia 312
causative agent 312
Status asthmaticus 240
Status epilepticus 915
diagnosis 916
etiology 916
management 916
subtypes 915
generalized 915
nonconvulsive 915
ST elevation myocardial infarction 402
Stem cells 620
clinical application 621
properties 620
types 621
Still's disease 672
Still's murmur 382t
Straight back syndrome (sbs) 526
Stroke 894
risk factors 895
types 895
Strongyloidiasis 174
clinical features 174
diagnosis 174
treatment 174
Subarachnoid hemorrhage 848, 904
clinical features 905
complications 906
etiology 905
investigations 905
management 906
Subclinical thyroid diseases 44
subclinical hyperthyroidism 44
effects 44
etiology 44
subclinical hypothyroidism 44
clinical consequences 44
indication for treatment 44
Subleukemic leukemia 572
Subpulmonic effusion 295
Substance-related disorders 1039
Sudden cardiac death 504
Sulfonamides 196
Superior vena cava syndrome 336
clinical features 336
investigation and diagnosis 336
management 336
Suppurative lung disease 279
bronchiectasis 279, 280
classification 279
clinical features 280
etiology 279
complications 282
investigations 281
management 282
antibiotic therapy 282
anti-inflammatory therapy 282
postural drainage 282
reversal of airflow obstruction 282
surgical treatment 282
respiratory system 281
Suppurative pneumonias 285
Suzman's sign 492
S wave 383
Swine flu 319
Sydenham's chorea 427
Synbiotics 736
Syncope 507
causes 508
investigations 508
mechanism 508
Syphilis 182
classification 182
primary syphilis 182
secondary syphilis 182
mode of transmission 182
source of infection 182
Systemic anaphylaxis 1077
anaphylactoid reactions 1078
causes 1077
clinical features 1079
mechanism 1078
treatment 1079
Systemic corticosteroids 237
Systemic lupus erythematosus 645
clinical features 646
cardiac manifestations 647
cutaneous manifestations 646
gastrointestinal features 647
hematologic manifestations 646
mucus membrane manifestations 646
musculoskeletal manifestations 646
neuropsychiatric features 647
ocular manifestations 647
other manifestations 647
pulmonary manifestations 647
renal manifestations 646
diagnostic criteria 648
drug-induced lupus 649
laboratory findings 647
management 649
Systemic sclerosis (scleroderma) 664
classification 664
clinical features 665
diagnosis 666
etiology 664
investigations 666
prognosis 667
treatment 666
Systolic blood pressure 422t
T
Tachycardia 474
AV node re-entry tachycardia 475
sinus tachycardia 474
supraventricular tachycardia 474
Takayasu arteritis 661
investigations 661
treatment 661
Tamm-Horsfall mucoprotein 825
Tests for gas exchange function 229
Tetanus 977
clinical features 978
investigations/diagnosis 978
management 978
Tetracycline 196
Tetralogy of Fallot 496
Thalassemia syndrome 552
classification 552
Thrombocytopenia 604
causes 604
general clinical manifestations 605
laboratory investigations 605
Thrombocytosis 607
Thrombotic thrombocytopenic purpura 612
clinical features 612
etiology and pathogenesis 612
laboratory findings 612
treatment 612
Thyroid disorders 35
Thyroid function tests 35
Thyroiditis 45
Hashimoto's thyroiditis 45
clinical features 46
investigations 46
treatment 46
Riedel's thyroiditis 46
clinical features 46
investigations 46
treatment 46
subacute thyroiditis 45
clinical features 45
laboratory findings 45
treatment 45
Thyroid ophthalmopathy 38
pathogenesis 38
signs 38
symptoms 38
Thyrotoxicosis 36
clinical features 38
clinical signs 38
etiology 37
treatment 38
Tinel's sign 928
Todd's paralysis 911
Total leucocyte count 130
Toxemia of pregnancy and HELLP 806
Toxic effects of INH 266
Toxic megacolon 732
causes 732
clinical features 732
complications 733
treatment 733
Toxidromes 981
Toxoplasmosis 168
Transfusion medicine 615
Transient ischemic attacks 904
clinical features 904
diagnosis 904
Transplantation immunology 1082
Transverse myelitis 955
Traube's semilunar space 295
Traveller's diarrhea 694
clinical features 694
etiology 694
treatment 695
Treatment of severe acute exacerbations 250
Treatment regimen for tuberculosis 270t
Tremor 944
causes 944
classification 944
types 944
Trichuris trichiura (whipworm) 172
clinical features 172
treatment 173
Triplet repeat expansion disorders 1057
Tropical splenomegaly syndrome 161, 164
Trousseau sign 817
Tuberculin skin test 264
assessment of activity of tuberculosis 265
latent tuberculosis 265
method 265
reading and interpreting the result 265
significance 265
Tuberculin test 263
Tuberculosis 257
Tuberculosis chemoprophylaxis 278
Tuberculosis in HIV infection 217
clinical features 217
treatment 217
Tuberculosis of the urinary tract 857
clinical features 858
etiology and pathology 857
investigation 858
treatment 858
Tuberculous meningitis 274
Tuberculous osteomyelitis 274
Tuberculous peritonitis 788
clinical features 789
investigations 789
treatment 789
Tuberculous pleural effusion 277, 297
clinical features 277
investigations 277
management 278
pathogenesis 277
Tubulointerstitial diseases 839
acute tubulointerstitial nephropathy 839
etiology 840
Tumor lysis syndrome 1010
Tumors of the nervous system 973
acoustic neuroma 974
clinical features 974
investigations 974
management 974
cerebellopontine (CP) angle tumors 973
clinical features 973
investigations 973
treatment 974
Turner's syndrome 68t
T wave 388
U
Ulcerative colitis 725
clinical features 726
investigations 726
microscopy 725
pathology 725
Unconjugated hyperbilirubinemia 738
Undulant fever 123
Uniparental disomy 1057
Unresolved/slow resolving pneumonia 309
Upper gastrointestinal (UGI) bleeding 686
basic investigations 688
clinical features 686
etiology 686
history 687
management 688
physical examination 687
Upper motor neurons 884
Urinary tract infections 188, 851
Urine tests 741
Urticaria 1075
clinical manifestation 1076
etiology 1075
management 1076
pathogenesis 1075
types 1075
U waves 389
V
Valvular heart disease 105, 430
aortic regurgitation 446
clinical features 447
etiology 446
investigations 449
aortic sclerosis 445
risk factors 446
treatment 446
aortic stenosis 443
classification 443
clinical features 443
etiology 443
investigations 445
pathophysiology 443
treatment 445
bicuspid aortic valve (BAV) disease 446
complications 446
treatment 446
combined mitral stenosis and mitral regurgitation 441
mitral regurgitation 437
clinical features 438
etiology 438
investigations 440
management 441
pathophysiology 438
mitral stenosis 431
etiology 431
mitral valve 430
mitral valve prolapse 442
clinical features 442
complications 442
investigations 442
management 442
pathogenesis 442
pulmonary stenosis 452
clinical features 452
etiology 452
investigations 453
pathophysiology 452
treatment 453
rheumatic mitral stenosis 431
clinical features 433
investigations 435
pathophysiology and hemodynamics 431
tricuspid regurgitation 451
causes 452
clinical features 452
etiology 452
treatment 452
tricuspid stenosis 451
clinical features 451
etiology 451
investigations 451
treatment 451
Variceal bleeding 689
Vascular dementia 1090t
Vasculitis 655
classification 655
clinical manifestations 656
Vectors in gene therapy 1059
Venezuelan encephalitis 141t
Veno-occlusive disease 792
clinical features 792
etiology 792
investigations 793
pathogenesis 792
Venous droppler study 107t
Venous thrombosis 520
Ventricular aneurysm 405
Ventricular fibrillation 481
Ventricular parasystole 473, 480
clinical features 480
diagnosis 480
etiology 480
treatment 480
types 480
Verner–Morrison syndrome 820
Vertigo 886
gait 886
abnormalities of 886
Violent cough 115
Viral encephalitis 926
Viral hepatitis 748
acute viral hepatitis 755
complications 755
chronic hepatitis 756
clinical feature 752
fulminant hepatitis 752
hepatitis A 749
etiology 749
extrahepatic manifestations 749
incubation period 749
mode of spread 749
prevention and prophylaxis 749
source of infection 749
hepatitis B 749
etiology 750
mode of transmission 750
prevention and prophylaxis 750
hepatitis C 751
etiology 751
mode of spread 751
hepatitis D 751
etiology 751
mode of spread 751
hepatitis E 751
etiology 751
outcome of infection 752
prevention and control 752
Viral infections 133
arthropod-borne viruses 141
chickenpox (varicella) 138
clinical features 138
complications 138
management 138
mode of transmission 138
chikungunya 147
clinical features 147
treatment 147
dengue 141
classification 142
clinical features 143
management 145
pathogenesis 142
source of infection 141
ebola virus disease 149
clinical features 149
mode of transmission 149
herpes viruses infecting humans 136
human papillomaviruses 139
diagnosis 140
mode of infection 140
treatment 140
types 140
infectious mononucleosis 136
clinical features 137
complications 137
etiology 137
investigations 137
Japanese encephalitis 147
clinical features 147
diagnosis 148
treatment 148
measles (rubeola) 133
clinical features 133
complication 133
diagnosis 133
treatment 134
mode of transmission 141
molluscum contagiosum 151
appearance of lesions 151
site of lesions 151
treatment 151
types 151
mumps 135
clinical features 136
complications 136
rubella (German measles) 134
clinical features 134
diagnosis 135
treatment 135
shingles (herpes zoster) 139
clinical features 139
complications 139
management 139
smallpox (variola) 148
clinical features 148
treatment 149
swine flu 149
complications 150
signs and symptoms 150
source of infection 150
treatment 150
Zika virus 151
clinical features 151
mode of spread 151
treatment 151
Viral meningitis/aseptic meningitis 925
clinical manifestations 925
etiology 925
laboratory diagnosis 925
treatment 925
Viral p24 antigen 212
Virchow's node 817
Virchow's triad 518
Visual hallucinations 1091
Vitamin D 53
autocrine metabolism 53
calcitriol 53
physiology 53
supplementing vitamin D 54
treatment of vitamin D deficiency 55
vitamin D in health and disease 53
Vitamin K 630
causes of vitamin K deficiency 630
treatment 630
Volume depletion 866
causes 866
clinical features 866
laboratory features 866
treatment 866
Voluntary dieting 69t
Vomiting 680
Von Willebrand's disease 611
W
Waardenburg syndrome 1113
Waldenstorm macroglobulinemia 591
clinical features 591
diagnosis 591
treatment 592
Water and electrolyte balance 821
Waterhouse-Friderichsen syndrome 110
Watery versus fatty versus inflammatory diarrhea 690
Watson's or water hammer pulse 372
WDHA syndrome 820
Weber's syndrome 898t
Wegener's granulomatosis 659, 671
clinical features 659
diagnosis 659
treatment 659
Weight loss 203, 684
Weil's syndrome. 130
investigations 130
treatment 131
Well's index 434
Well's scoring system 518
Western blot 198
Western blot assays 212
Western equine encephalitis 141t
West Nile encephalitis 141t
Whipple's disease 715
clinical features 715
investigations 715
treatment 715
Whipple's triad 818
White blood cells 827
WHO clinical staging of HIV infection 203t
Whooping cough 115
clinical features 115
catarrhal phase 115
convalescence phase 116
paroxysmal phase 115
complications 116
management 116
Willis-Ekbom disease 1044
Wilson disease 739, 799
clinical features 799
etiology 799
investigations 800
pathology 799
Wiskott-Aldrich syndrome (WAS) 1072
Wolff-Parkinson-White syndrome 479
Wood's lamp 1118
Woolsorter's disease 112
X
Xanthochromia 921, 927
Xanthogranulomatous pyelonephritis 856
Xeroderma pigmentosum 1114
Xerostomia 1121
effects 1121
etiology 1121
management 1121
X-linked agammaglobulinemia 1071
X-linked recessive disease 1072
Y
Yellow fluorescence 1107
Yellow nails syndrome 280
Young's syndrome 280
Young stroke 902
Z
Z deformity 639
Zidovudine 219
Zidovudine-induced anemia 629
Ziehl-Neelsen stain 257
Zika virus 151
Zollinger-Ellison syndrome 819
Zone of hyperesthesia 947
×
Chapter Notes

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Nutrition and Environmental MedicineCHAPTER 1

 
VITAMIN A
Q. Write a short essay/note on clinical features, diagnosis, and treatment of vitamin A deficiency.
Vitamin A is a fat-soluble vitamin. Vitamin A is the name given to a group of related compounds and mainly includes retinoids and carotenoids.
  • Retinoids/Retinol (vitamin A alcohol): Retinoid is the generic term that encompasses vitamin A in its various forms and both natural and synthetic chemicals that are structurally related to vitamin A, but may not necessarily have vitamin A-like biologic activity. Its oxidized metabolites, retinaldehyde and retinoic acid (vitamin A acid) are biologically active compounds. It is the chemical name given to vitamin A. It is the transport form and, as retinol ester, also the storage form.
  • Carotenoids: There are more than 600 carotenoids in nature, and approximately 50 of these can be metabolized to vitamin A. The most common carotenoid in the food having provitamin A activity is β-Carotene. Major portions of carotenoids are absorbed as such and are stored in liver and fat.
 
Sources of Vitamin A
  • Animal-derived foods: Preformed retinol is found only in foods of animal origin. Food source include liver, fish, milk, eggs, butter, and cheese.
  • Yellow and green leafy vegetables: Vegetable sources of provitamins A carotenoids include dark green and deeply colored fruits and vegetables. Moderate cooking of vegetables enhances carotenoid release for uptake in the gut.
  • Absorption of carotenoid is facilitated by fat in a meal.
 
Functions of Vitamin A
Vitamin A has several metabolic roles. The main functions of vitamin A in human are as follows:
  • Maintenance of normal vision: Vitamin A is essential for vision (especially dark adaptation).
  • Host resistance to infections: Keratinization of mucous membranes in vitamin A deficiency adds up to the risk to infections. Retinol binding protein (RBP) is a negative ‘acute phase protein’.
  • Immune function: Vitamin A has ability to stimulate the immune system. Retinoids are needed for normal growth, fetal development, fertility, hematopoiesis and immune function.
  • Control of cell growth and differentiation: Maintenance of the surface linings of the eyes, epithelial cell growth and repair, and the epithelial integrity of the respiratory, urinary, and intestinal tracts. In vitamin A deficiency, mucus-secreting cells are replaced by keratin-producing cells and this process is known as squamous metaplasia.
  • Regulation of lipid metabolism: It is a key regulator of fatty acid metabolism, including fatty acid oxidation in fat tissue and muscle, adipogenesis, and lipoprotein metabolism.
  • Antioxidant: Retinoids, β-carotene, and some related carotenoids act as photoprotective and antioxidant agents.
  • Other functions: Bone growth, reproduction and it also important for embryonic development and the regulation of adult genes.
  • Tretinoin i.e. all-trans retinoic acid (ATRA) is also used to treat acute promyelocytic leukemia (APL), isotretinoin, is used to treat acne.
 
Vitamin A Deficiency (Table 1.1)
 
Clinical Features/Manifestations
Effects in the eye:
  • Bitot's spots: These areas of abnormal squamous cell proliferation and keratinization of the conjunctiva can be seen in young children with vitamin A deficiency (VAD).
  • Blindness due to retinal injury: Vitamin A has a major role in photo transduction. Vitamin A deficiency leads to a lack of visual pigments; this reduces the absorption of various wavelengths of light, resulting in blindness.2
  • Poor adaptation to darkness (nyctalopia): Can lead to night blindness, which is an early symptom.
  • Xerophthalmia (dry eye): Results from keratinization of the conjunctiva.
  • Keratomalacia: In advanced deficiency; the cornea becomes hazy and can develop erosions, which can lead to its destruction (keratomalacia).
TABLE 1.1   Causes of vitamin A deficiency
Primary causes
Secondary causes
  • Prolonged dietary deprivation
  • Sprue
  • Vegetarians
  • Cystic fibrosis
  • Refugees
  • Pancreatic insufficiency
  • Chronic alcoholics
  • Duodenal bypass
  • Toddlers
  • Chronic diarrhea
  • Preschool children
  • Bile duct obstruction
  • Giardiasis, and cirrhosis
Increased susceptibility to infections:
Keratinization of the mucous membranes of respiratory tracts and urinary tract takes place, increasing the susceptibility to infections (e.g. respiratory infections).
Other features: Fatigue, anemia, diarrhea, decreased growth rate, decreased bone development and infertility.
 
Laboratory Investigations
  • Serum retinol level: Normal range is 28 to 86 μg/dL (1 to 3 µmol/L). The level decreases in vitamin A deficiency.
  • Albumin levels are indirect measures of vitamin A levels.
  • Complete blood count (CBC) with differential count to be done if there is a possibility of anemia, infection, or sepsis.
 
Diagnosis
  • It is mainly on the basis of the clinical features.
  • Blood levels of vitamin A will usually be low.
  • Response to replacement therapy is the best way for the diagnosis.
Prophylactic vitamin A dose of 60 mg every 6 months is recommended in high-risk individuals and patients with malabsorption syndrome require vitamin A supplements.
 
Prevention
Prophylactic supplements of vitamin A palmitate in oil
  • Children between 1 and 5 years of age: 60,000 RAE (retinol activity equivalents) (200,000 IU) per oral every 6 month
  • Infants < 6 months: can be given a one-time dose of 15,000 RAE (50,000 IU)
  • 6 to 12 months: can be given a one-time dose of 30,000 RAE (100,000 IU).
 
Vitamin A Toxicity
Q. Write short essay/note on hypervitaminosis A and its signs.
  • Types of toxicity: Vitamin A toxicity can be acute (usually due to accidental ingestion by children) or chronic. Both types cause headache and increased intracranial pressure (pseudotumor cerebri).
    • Acute toxicity also causes nausea and vomiting. Single doses of 300 mg in adults or 100 mg in children can be harmful.
    • Chronic toxicity also causes changes in skin, hair (loss), and nails; liver and bone damage; double vision, ataxia, hyperlipidemia and vomiting.
    • Retinol is teratogenic and incidence of birth defects in infants is high with vitamin A intakes of >3 mg a day during pregnancy.
  • Diagnosis is usually clinical. Unless birth defects are present, adjusting the dose almost always leads to complete recovery.
Recommended dietary allowances (RDAs)/adequate intake of fat soluble vitamins for individuals (Table 1.2).
Carotenemia is common among infants and toddlers who eat large amounts of carrots and green leafy vegetables. It can be confused with jaundice, but discoloration of skin spontaneously resolves once the intake of food is reduced.
TABLE 1.2   Recommended dietary allowances (RDAs)/adequate intake of fat soluble vitamins for individuals
Life stage
Vitamin A (RAE*)
Vitamin D (µ/d)
Vitamin E (µ/d)
Vitamin K (µ/d)
Infants
400-500
5
4-5
2-2.5
Children (1-13 yr)
300-600
5
6-11
30-603
Males (>14 yr)
900
5-15
15
75-120
Females (>14 yr)
600-700
5-15
11-15
75-90
Pregnancy
750-770
5
15
75-90
Lactation
1200-1300
5
19
75-90
*1 RAE (retinol activity equivalents) = 1 µg retinol, 12 µg β-carotene; 1 µg calciferol = 40 IU vitamin D.
 
VITAMIN B COMPLEX
 
Thiamine (B1)
Thiamine is an important water-soluble vitamin.
 
Functions
  • Involved in carbohydrate, fat, amino acid, glucose, and alcohol metabolism.
  • Vitamin B1 is essential for the coenzyme, thiamine pyrophosphate (TPP). It is required for the following reactions:
    • Decarboxylation of pyruvate (glycolytic pathway) to acetyl CoA (Krebs cycle)
    • Transketolase in the hexose monophosphate (HMP/pentose) shunt pathway
    • Decarboxylation of α-ketoglutarate to succinate (Krebs cycle).
  • Has an additional role in neuronal conduction.
TABLE 1.3   Causes of thiamine deficiency
Lack of thiamine intake
  • Food containing a high level of thiaminase, including milled rice, raw freshwater fish, raw shellfish, and ferns
  • Food high in antithiamine factor, such as tea, coffee, and betel nuts
  • Alcoholic state
  • Starvation state
Increased consumption states
  • Diets high in carbohydrate or saturated fat intake
  • Pregnancy and lactation
  • Hyperthyroidism
  • Fever—severe infection
  • Increased physical exercise
Increased depletion
  • Diarrhea
  • Peritoneal dialysis, hemodialysis, diuretic therapies
  • Hyperemesis gravidarum
Decreased absorption
  • Chronic intestinal disease
  • Alcoholism
  • Malnutrition
  • Gastric bypass surgery
  • Malabsorption syndrome—celiac and tropical sprue
 
Sources
  • These vitamins can be produced by plants and some microorganisms. However, animals cannot synthesize them.
  • Human beings require thiamine from diet, though small amounts may be obtained from synthesis by intestinal bacteria.
  • Whole wheat flour, unpolished rice, cereals, grains, beans, nuts and yeast are the good sources of thiamine. Milled rice and grains contain little or no thiamine. Thus, thiamine deficiency is more common in individuals who rely heavily on a rice-based diet.
  • It is also present in liver, meat and eggs.
TABLE 1.4   Clinical syndromes of thiamine deficiency
1. Wet beriberi—high cardiac output failure
2. Dry beriberi—peripheral neuropathy
3. Wernicke's encephalopathy
4. Korsakoff's psychosis
5. Leigh syndrome
 
Requirement
  • Up to 30 mg of thiamine can be stored in body tissues. Required daily allowance (RDA) is 1–1.5 mg/day
  • Requirement increases with increased carbohydrate intake, pregnancy and lactation, smoking, alcoholism, prolonged antibiotic intake, serious or prolonged illness.
 
Causes of Thiamine Deficiency (Table 1.3) Consequences of Thiamine Deficiency
Impaired glucose oxidation
  • Cells cannot metabolize glucose aerobically to generate energy as ATP. Neuronal cells are most susceptible, since they depend almost exclusively on glucose for energy requirements.
  • Causes an accumulation of pyruvic and lactic acids, which produce vasodilatation and increased cardiac output.
 
Clinical Syndromes of Thiamine Deficiency (Table 1.4)
Q. Write short essay/note on clinical features of beriberi/vitamin B1 (thiamine) deficiency.
  1. Wet (cardiovascular) beriberi: Wet beriberi is the term used for the cardiovascular involvement of thiamine deficiency.
    • First effects are vasodilatation, tachycardia, a wide pulse pressure, sweating, warm skin, and lactic acidosis.
    • Later, congestive heart failure develops, causing orthopnea and pulmonary and peripheral edema. Marked cardiomegaly is present.4
    • Edema: Initially, there is edema of the legs, but later it can involve the whole body, with ascites and pleural effusions. Edema is caused by the metabolites such as pyruvate and lactate, which cause extreme peripheral vasodilatation and leakage of fluid through capillaries. Vasodilatation can continue, sometimes resulting in shock.
      Infantile beriberi occurs in infants (usually by age 3 to 4 weeks) who are breastfed by thiamine-deficient mothers. Heart failure can suddenly develop and present with edema, aphonia, tachycardia, tachypnea and absent deep tendon reflexes. If prompt treatment is not given, death occurs quickly. Treatment is to give thiamine to the nursing mother, which passes to the infant through the breast milk.
      Shoshin beriberi: A more rapid form of wet beriberi is termed acute fulminant cardiovascular beriberi, or Shoshin beriberi. The predominant injury is to the heart, and rapid deterioration follows the inability of the heart muscle to satisfy the body's demands because of its own injury. The patient does not develop edema but may develop cyanosis of the hands and feet, distension of neck veins, tachycardia, veins, restlessness, and anxiety.
  2. Dry beriberi: Dry beriberi usually presents insidiously with symmetrical peripheral neuropathy.
    • Initial symptoms: They are bilateral and roughly symmetric and include heaviness and stiffness of the legs.
    • Later: Weakness, numbness, and pins and needles (occurring in a stocking-glove distribution).
    • Distribution of neuropathy: They affect predominantly the lower extremities, beginning with paresthesias in the toes, burning in the feet (severe at night), muscle cramps in the calves, pains in the legs, and plantar dysesthesias.
    • Physical signs: Calf muscle tenderness, difficulty rising from a squatting position, and decreased vibratory sensation in the toes. The ankle jerk reflexes are lost.
    • Histological examination of involved nerve shows noninflammatory degeneration of myelin sheaths (demyelination).
    • Continued deficiency worsens polyneuropathy and can eventually involve the nerves of the arms (wrist and/or foot drop). Deficiency may also cause degeneration of thalamus, mammillary bodies, and cerebellum.
      Biochemical tests:
    • Measurement of thiamine, pyruvate and lactate levels in blood.
    • Transketolase activity of whole blood or erythrocyte.
Q. Write short essay/note on management/treatment of beriberi/vitamin B1 (thiamine) deficiency.
Q. Write short essay/note on Wernicke's encephalopathy.
  1. Wernicke's encephalopathy: It is an acute neuropsychiatric condition due to an initially reversible biochemical brain lesion caused by depletion of vitamin B1 (thiamine).
    Causes (refer Table 1.3)
    Clinical features:
    • Wernicke's encephalopathy (WE) is a triad of nystagmus, ophthalmoplegia, and ataxia, along with confusion. Impairment in the synthesis of one of the important enzymes of the pentose phosphate pathway (erythrocyte transketolase) may explain such a predisposition.
    • Encephalopathy characterized by profound disorientation, indifference, and inattentiveness, impaired memory and learning are also evident. In untreated patients will progress through stupor and coma to death.
    • Oculomotor dysfunction: Nystagmus, lateral rectus palsy, and conjugate gaze palsies reflect lesions of the oculomotor, abducens, and vestibular nuclei.
    • Gait ataxia: Ataxia primarily involves stance and gait and is likely due to a combination of polyneuropathy, cerebellar involvement, and vestibular dysfunction.
Diagnosis: Diagnosis is confirmed by measurement of the circulating thiamine concentration or transketolase activity in red cells using fresh heparinized blood.
  1. Korsakoff's psychosis/syndrome
    Q. Write short note on Korsakoff's psychosis/syndrome.
    • Korsakoff's psychosis (KS) is caused by deficiency of thiamine with involvement of central nervous system.
    • Memory disturbances: It is predominantly associated with defect in retentive memory (severe defect in storing new information and learning). Thus, there are disturbances of short-term memory. There is marked deficits in anterograde and retrograde memory, apathy, an intact sensorium, and relative preservation of long-term memory and other cognitive skills.
    • Confabulation: It presents clinically by hallucinations and confabulation (in some but not all cases). Confabulation is a memory disturbance, characterized by the production of fabricated, distorted or misinterpreted memories about oneself or the world, without the conscious intention to deceive. Attention and social behavior are relatively preserved. Affected individuals can carry on a socially appropriate conversation that may seem normal to an unsuspecting spectator.
    • The syndrome is common in chronic alcoholics but may also be seen with thiamine deficiency resulting from gastric disorders, including carcinoma, chronic gastritis, or persistent vomiting.
    • Outcome: Varies. Complete or almost complete recovery occurs in less than 20% of patients. In the remainder of patients, the recovery is gradual and incomplete.
  1. Leigh syndrome: Thiamine deficiency may be associated with a progressive subacute necrotizing encephalomyopathy. It is a sporadic mitochondrial disorder with a subacute neurologic course. Symptoms include ataxia, dysarthria, areflexia, disorders of movement, atrophy of muscle and weakness.
 
Pellagra
Q. Write short essay/note on clinical features and management of niacin deficiency (pellagra).
Vitamin B3 niacin (nicotinamide) deficiency causes metabolic encephalopathy called pellagra. It is found mostly in populations in which corn is the major source of energy in parts of China, Africa, and India. Pellagra means raw skin.
 
Clinical Features
Pellagra has been easily remembered a disease of four Ds namely 1) dermatitis, 2) diarrhea, 3) dementia (depression) and 4) death. However, these features are not always observed and the mental changes are not a true dementia.
  1. Skin manifestations:
    • Casal's necklace or collar rash: Characteristic skin rash develops that is hyperpigmented and scaling that develops in skin areas exposed to sunlight (similar in color to sunburn). This rash forms a ring around the neck and is termed as Casal's necklace.
    • Dermatitis: Lesions of the skin may progress to vesiculation, cracking (ulceration), exudation and secondary infection.
    • Symmetrical chronic thickening, dryness and pigmentation may be seen on the dorsal surfaces of the hands.
  2. GI tract:
    • Diarrhea: It may be in part due to proctitis and in part due to malabsorption. It is often a feature accompanied by anorexia, nausea, glossitis and dysphagia indicating noninfective inflammation of the entire gastrointestinal tract.
    • Other features include raw, painful, bright red tongue (glossitis), angular stomatitis, vaginitis, esophagitis, vertigo, and burning dysesthesias.
  3. Dementia: This occurs in chronic severe deficiency and may also develop hallucinations and acute psychosis. Milder deficiency may present with depression, apathy and sometimes thought disorders. Other neurologic symptoms include insomnia, anxiety, disorientation, tremor delusions, dementia, and encephalopathy.
6
 
Diagnosis
  • Diagnosis in endemic region depends on the clinical features. Other vitamin deficiencies can also produce similar changes (e.g. angular stomatitis).
  • Dramatic improvement: The response is usually rapid in the skin (within 24 hours), diarrhea and a striking improvement occurs in the patient's mental state occurs with nicotinamide treatment.
Vitamin B12 and Folic acid discussed under Chapter 8.
 
Vitamin C
Q. Write short essay/note on vitamin C and clinical features of scurvy.
Vitamin C (ascorbic acid) is a water-soluble vitamin
 
Functions
  • Formation of collagen from procollagen. It is essential for wound healing and facilitates recovery from burns. It is needed for hydroxylation of proline to hydroxyproline (in protocollagen) and lysine to hydroxylysine (in mature collagen).
  • Antioxidant properties: Ascorbic acid is the most active powerful reducing agent controlling the redox potential within cells.
  • It is involved in intracellular electron transfer and supports immune function.
  • Promotes absorption of nonheme iron.
  • It is needed for the formation of carnitine, hormones, and amino acids.
  • Formation of intercellular cement substances in connective tissues, bones, and dentin, when defective, resulting in weakened capillaries with subsequent hemorrhage and defects in bone and related structures.
 
Causes of Vitamin C Deficiency
  • Infants fed only on boiled cow's milk during the first year of life are at risk.
  • Individuals, who do not eat vegetables such as elderly, people who live alone (singly) and chronic alcoholics.
  • Pregnant and lactating women and those with thyrotoxicosis require more vitamin C because of increased utilization.
  • Individuals at risk of deficiency:
    • Anorexia nervosa or anorexia from other diseases such as AIDS or cancer
    • Type 1 diabetes require increased vitamin C
    • Patients undergoing peritoneal dialysis and hemodialysis
    • Diseases of small intestine such as Crohn's, Whipple, and celiac disease.
 
Deficiency of Vitamin C-Scurvy
Scurvy is caused by deficiency of vitamin C.
Types of scurvy: Adult scurvy and infantile scurvy.
Clinical features of adult scurvy
  • Early symptoms may be nonspecific, with malaise, weakness, lethargy and muscle pain (myalgias may be due to reduced production of carnitine).
  • Bone disease: More common in growing children and manifests after 1–3 months. It is characterized by deranged formation of osteoid matrix and bone pain. Fractures, dislocations, and tenderness of bones are common in children.
  • Hemorrhages: Hemorrhaging is a hallmark feature of scurvy and can occur in any organ. Hair follicles are one of the common sites of cutaneous bleeding. Marked tendency to bleed into the skin (easy bruising, petechiae, ecchymosed, perifollicular hemorrhages), bleeding into muscles, joints and underneath peritoneum. Bruising and hemorrhage may be spontaneous. Most commonly on the legs and buttocks where hydrostatic pressure is the greatest.
  • Delayed/poor wound healing and breakdown of old scars.
  • Anemia: It may cause high-output heart failure.
  • Gums: Inflamed spongy gums (gum swelling) friability, bleeding and infection with loosening of teeth; mucosal petichiae are common.
  • Skin changes: Roughness, keratosis of hair follicles with ‘corkscrew’ hair, perifollicular hemorrhages.
  • 7Nails: Splinter hemorrhages.
  • Other features: Emotional changes, shortness of breath.
Clinical features of infantile scurvy (Barlow's disease)
  • Subperiosteal hemorrhage into shafts of long bones.
  • Scorbutic rosary denotes enlargement of costochondral junctions, which are tender. May be associated with pectus excavatum.
  • Retrobulbar, subarachnoid and intracerebral hemorrhages.
  • Painful limbs giving rise to ‘pseudoparalysis’.
Laboratory investigations and diagnosis
  • Diagnosis is usually made clinically in a patient who has skin or gingival signs and is at risk of vitamin C deficiency.
  • Plasma ascorbic acid is very low.
  • Vitamin C level of <11 μmol/L (0.2 mg/100 mL).
  • Anemia: It may be normochromic, normocytic (due to bleeding), megaloblastic (due to reduced erythropoiesis) and microcytic hypochromic anemia (due to impaired iron absorption and impaired heme synthesis).
  • Capillary fragility test can be checked by inflating a blood pressure cuff and looking for petechiae on the forearm.
  • Bleeding time, clotting time and Prothrombin time: To rule out other bleeding disorders.
  • Imaging Studies: The findings include 1) loss of trabeculae results in a ground-glass appearance, 2) thinning of cortex, 3) a line of calcified, irregular cartilage (white line of Frankel) may be visible at the metaphysis, and 4) the epiphysis may be compressed.
 
VITAMIN D
Vitamin D is a fat-soluble vitamin. It is required for the maintenance of adequate plasma levels of calcium and phosphorus to support metabolic functions, bone mineralization, and neuromuscular transmission.
Physiology (refer page 53 of Chapter 2)
Vitamin D exists in 2 activated sterol forms (Box 1.1).
Main steps of vitamin D metabolism
  • Less effective as precursor to 1,25 (OH)2-Vit D
  • In liver: Vitamin D (D3) is converted into 25-hydroxyvitamin D (25 (OH) D3) (calcidiol) by the action of 25-hydroxylases.
  • The enzyme 1α-hydroxylase (mitochondrial cytochrome P450) converts 25-hydroxyvitamin D (25 (OH) D3) into 1,25-dihydroxyvitamin D, (1,25(OH)2D3) (calcitriol). Previously thought exclusively renal.
  • Requires two factors
    • 25OH-Vit D3-1-alpha-OHase
    • Vitamin D receptor (VDR)
 
Functions
  1. Regulation of plasma levels of calcium and phosphorus: The main functions of 1, 25-dihydroxyvitamin D on calcium and phosphorus homeostasis are:
    • Stimulates intestinal absorption of calcium: 1, 25-dihydroxyvitamin D stimulates intestinal absorption of calcium in the duodenum through the interaction of 1, 25-dihydroxyvitamin D with nuclear vitamin D receptor.
    • Stimulates calcium reabsorption in the kidney: 1, 25-dihydroxyvitamin D increases calcium influx in distal tubules of the kidney.
    • Interaction with PTH in the regulation of blood calcium.
    • Mineralization of bone: Vitamin D plays a role in the mineralization of osteoid matrix and epiphyseal cartilage in both flat and long bones. Vitamin D stimulates osteoblasts to produce the calcium-binding protein osteocalcin, which is involved in the deposition of calcium during development of bone.
  2. 8Antiproliferative effects: The VDR (vitamin D receptor) is expressed in the parathyroid gland, and 1, 25(OH) 2D has an antiproliferative effect on parathyroid cells and it suppresses the transcription of the parathyroid hormone gene.
  3. Immunomodulatory: Vitamin D is involved in the innate and adaptive immune system.
 
Vitamin D Deficiency
Q. Write briefly on clinical features, investigations, treatment and prevention of rickets.
 
Causes of Vitamin D Deficiency (Box 1.2)
Disease Caused
  • In children: Deficiency of vitamin D in a growing child before the epiphyses has fused results in failure of growing bone to mineralize.
    • Rickets: Bone softening disease, deformity of long bones occurs.
  • In adults:
    • Osteomalacia: Bone thinning disorder, proximal muscle weakness and bone fragility.
    • Osteoporosis: Decrease of bone mineralization and increased bone fragility.
 
Rickets in Children (Fig. 1.1)
zoom view
Fig. 1.1: Features of rickets
In children, before the closure of epiphyses, vitamin D deficiency causes retardation of growth associated with an expansion of the growth plate known as rickets.
Gross skeletal changes in rickets
It depends on the severity and duration of the vitamin D deficiency and also the stresses to which individual bones are subjected.
During the nonambulatory stage of infancy
  1. Head:
    • Craniotabes: The skull appears square and box-like. Delayed closure of anterior fontanelle, frontal and parietal bossing.
    • Frontal bossing: Excess of osteoid produces frontal bossing and a squared appearance to the head.
    • Delayed eruption of primary teeth, enamel defects and caries teeth.
  2. Chest:
    • Rachitic rosary: Overgrowth of cartilage or osteoid tissue at the costochondral junction causes deformation of the chest producing the ‘rachitic rosary’.
    • Pigeon breast/chest deformity: The weakened metaphyseal areas of the ribs are subject to the pull of the respiratory muscles and thus bend inward. This creates anterior protrusion of the sternum producing pigeon breast deformity (pectus carinatum).
    • Harrison's sulcus/groove: It is due to the muscular pull of the diaphragmatic attachments to the lower ribs.
    • Respiratory infections and atelectasis.
During the nonambulatory stage
  • Lumbar lordosis: This occurs when an ambulating child develops rickets. It is characterized by deformities affecting the spine, pelvis, and tibia. Scoliosis, kyphosis and lordosis.
  • Bowing of the legs: Due to affection of tibia, knock knees, anterior curving of legs.
Extraskeletal manifestations
  • Seizures and tetany: Secondary to hypocalcemia in Vitamin D deficiency rickets and VDDR type 1.
  • Hypotonia and delayed motor development: In rickets developing during infancy.
  • Protuberant abdomen, bone pain, waddling gait and fatigue.
  • Asymptomatic: Detected on radiological evaluation.
9Investigations
  • Wrist radiograph: Findings include 1) lower ends of the shaft of radius and ulna become splayed, 2) epiphyseal surfaces—fuzzy and ill-defined, and 3) unossified zone between shaft and radial epiphysis—widened (‘saucer’ deformity).
  • Blood:
    • Serum calcium: Low
    • Serum phosphate: Low (due to associated secondary hyperparathyroidism).
    • Serum alkaline phosphatase: Increased due to increased osteoblast activity.
    • Plasma 25-hydroxyvitamin D3 level: Low in most of the cases.
Prevention
  • Adequate consumption of vitamin D (1000-5000 IU/day).
  • Adequate exposure to sunlight (from 30 minutes to 2 hours/week for infants).
 
Osteomalacia
Q. Discuss the causes, clinical features, investigations and treatment in case of osteomalacia.
  • Vitamin D deficiency in adults is accompanied by hypocalcemia and hypophosphatemia which result in impaired (hypo/under/inadequately) mineralization of bone matrix proteins, a condition known as osteomalacia. Thus, osteomalacia is a disorder of mineralization of the organic matrix of the skeleton in adults when the epiphyseal growth plates have closed. In contrast, in rickets, the growing skeleton is involved.
  • Hypomineralized bone matrix is biomechanically inferior (weak) to normal bone. This bone is prone to bowing and gross skeletal fractures or microfractures which are most likely to affect vertebral bodies and femoral neck.
Etiology
Many disorders (Table 1.5) can result in osteomalacia, mainly through alteration in vitamin D metabolism or because of phosphate wasting.
Clinical features
  • Bone pains, muscle weakness, fractures of bones with minor trauma.
  • Pain in the hip may cause antalgic gait.
  • Weakness of proximal muscle results in wadding gait and may resemble primary muscle disease.
  • Collapse of vertebrae causes local pain and deformity.
  • Softening of skeleton may produce deformities such as kyphosis, coxa vara, pigeon chest and triradiate pelvis with a narrow public arch.
Laboratory investigations
Blood
  • Serum calcium: Low or normal. Secondary hyperparathyroidism releases calcium from bone and increased resorption of calcium by the kidney. This results in maintenance of normal serum calcium in most patients.
  • Serum phosphorus: Low.
  • Serum alkaline phosphatase: Raised.
  • Serum 25-hydroxyvitamin D3 levels: Low (<30 ng/mL).
  • PTH levels: Raised.
TABLE 1.5   Causes of osteomalacia
Nutritional abnormalities: Dietary deficiency of vitamin D, parenteral nutrition
Malabsorption: Tropical sprue, Celiac disease, hepatobiliary diseases, pancreatic insufficiency
Disorders of Vitamin D metabolism: Vitamin D dependency type I and type II, anticonvulsants, chronic renal failure
Acidosis: Distal renal tubular acidosis (type I)
Phosphate depletion: Use of non-absorbable antacids, tumor-associated osteomalacia
Others: Multiple myeloma, nephrotic syndrome, lead poisoning, inadequate sun exposure
Urinary excretion of calcium: Reduced
Radiological findings
  • Bone density: Reduced (osteopenia).
  • Epiphyseal growth plate: Increased in thickness, cupped and hazy at the metaphyseal border.
  • Cortical thinning: Due to secondary hyperparathyroidism.
  • Other features: Presence of nontraumatic fractures, radiolucent bands called pseudofractures (Looser's zones).
  • 10Bone scan may be normal or show discrete foci of increased radionuclide uptake.
  • Bone mineral density as assessed by dual-energy X-ray absorptiometry (DEXA) is reduced at spine, hip and forearm, with the maximum deficits at the cortical-rich bone in the forearms.
 
Hypervitaminosis D
Q. Write short answer on hypervitaminosis D.
 
Clinical Features
Hypervitaminosis D causes hypercalcemia, which manifest as 1) nausea and vomiting, 2) excessive thirst and polyuria, 3) severe itching, 4) joint and muscle pains, 5) disorientation and coma, and 6) metastatic calcifications.
 
TRACE ELEMENTS
 
Introduction
  • Trace elements are elements which occur or function in living tissues in concentrations most conveniently expressed in µg/l
  • The term ‘trace’ is used to concentrations of element not exceeding 250 µg/gram of extracellular matrix. Trace elements are naturally occurring, homogeneous, inorganic substance required in humans in amounts less than 100 mg/day
  • Bioavailability of minerals is low in vegetarian diet and excess amounts are injurious to health.
 
Classification of Trace Elements (Box 1.3)
  • There are about 15 trace elements of which only 10 are essential nutrients in humans. These include: Iron, zinc, copper, chromium, selenium, iodine, fluorine, manganese, molybdenum and cobalt.
  • Biochemical functions of trace elements: Acts as components of prosthetic groups or as cofactors for enzymes.
TABLE 1.6   Iron distribution in healthy young adults
Pool
Amount
Total body content
  • 4–6 g
Functional
  • Hemoglobin
  • Myoglobin
  • Iron dependent enzymes: Cytochrome oxidase, xanthine oxidase and peroxidase
  •  
  • 68%
  • 3%
  • 0.2%
Storage
  • Ferritin
  • Hemosiderin
  •  
  • 13%
  • 12%
 
Iron
Q. Write short note on daily requirement of iron and important dietary sources of iron.
  • Most essential trace element.
  • Iron distribution in healthy young adults is given in Table 1.6.
  • Daily body requirement: 0.5–2 mg/day, 3–5 mg/day (pregnancy).
  • Daily excretion: 0.9 mg/day, 1.3 mg/day (during menses).
  • Site of absorption: From the duodenum and proximal jejunum.
  • Deficiency state:
    • Asymptomatic
    • Anemia, (discussed under chapter 8) weakness, headache, irritability, and varying degrees of fatigue and exercise intolerance.
 
Acute Iron Poisoning
  • Develops when iron level is exceeds 60 mg/kg elemental iron
  • Clinical features: Vomiting, abdominal pain, bloody diarrhea, shock, dehydration, cyanosis, acidosis, and coma. Can cause hepatotoxicity and bowel obstruction.
11
 
Fluorosis
Q. Write short note on fluorosis and its radiological signs.
  • Fluorine: Fluorine's ionic form is known as fluoride. It is component of bone mineral and alters its physical characteristics. Fluoride helps to prevent dental caries, because it increases the resistance of the enamel to acid attack. Requirement in adults is between 1.5 and 4 mg/day and 96% of fluorides in the body found in bone and teeth.
  • Deficiency: Intake of <0.1 mg/day in infants and <0.5 mg/day in children predisposes to an increased incidence of dental caries.
  • Toxicity: Results in fluorosis. This develops when fluoride content in the water is high (>3 to 5 ppm).
    • Acute ingestion of >30 mg/kg body weight usually manifests with gastrointestinal symptoms like diarrhea, vomiting leading to renal failure and may cause death.
    • Dental fluorosis: It is characterized by mottling of teeth where the enamel loses its luster, appears teeth chalky white with transverse yellow bands. It becomes rough, pigmented, pitted and brittle (fluorite teeth).
    • Skeletal fluorosis: Its features are:
      • Sclerosis of bones (especially of spine, pelvis and limbs).
      • Calcification of ligaments, interosseous membrane and tendinous insertions.
      • Osteoporosis with brittle bones.
      • Severe pain and stiffness in joints, stiffness in neck and backbone, bow legs. Other features are weakness, anemia and weight loss.
TABLE 1.7   Causes of angular stomatitis
  • Iron deficiency anemia
  • Secondary infection of Candida albicans, Staphylococcus
  • Vitamin deficiency:
    • Riboflavin (B2) deficiency
    • Pyridoxine (B6) deficiency
    • Niacin deficiency (pellagra)
  • Herpes labialis at the angle of mouth
  • Angular stomatitis is associated with cheilosis in niacin deficiency and pellagra
 
Angular Stomatitis
Q. Write short note on angular stomatitis.
  • Angular stomatitis refers to cracking of the epithelium at the edge of the lips. It presents with erythema, maceration, scaling, and fissuring at the corners of the mouth. Most commonly bilateral and very painful.
  • Causes of angular stomatitis (Table 1.7)
 
ENTERAL AND PARENTERAL NUTRITION SUPPORT
Some form of nutritional support is needed for patients who cannot eat, should not eat, will not eat or cannot eat enough.
 
Indications for Nutritional Support
  • Severely malnourished patients on admission to hospital
  • Moderately malnourished patients who are not expected to eat for more than 3–5 days (because of their physical illness).
  • Normally nourished patients not expected to eat for more than 5 days or to eat less than half their intake for more than 8–10 days.
 
Types of Nutritional Support
  • Enteral nutrition should be used if the gastrointestinal tract is functioning normally.
  • Parenteral nutrition.
 
Enteral Nutrition (EN)
  • Patients who are not able to swallow may need artificial nutritional support (e.g. after acute stroke or throat surgery, or long-term neurological disorders such as motor neuron disease and multiple sclerosis).
  • Whenever possible, the enteral route should be used.
Definition
Nutritional support via placement of tubes through the nose, esophagus, stomach, or intestines (duodenum or jejunum).
Prerequisite: Must have functioning GI tract.
Advantages and disadvantages of enteral nutrition (Table 1.8)
TABLE 1.8   Advantages and disadvantages of enteral nutrition
Advantages
Disadvantages
  • Intake easily/accurately monitored
  • Provides nutrition when oral intake is not possible or adequate
  • Less cost than parenteral nutrition
  • Readily available
  • Reduces risks associated with disease state
  • Preserves gut integrity and immunologic function
  • Decreases likelihood of bacterial translocation
  • Increased compliance with intake
  • Decreases the risk of multi-organ failure in intensive care patients
  • GI, metabolic, and mechanical complications:
    • Tube migration
    • Increased risk of bacterial contamination
    • Tube obstruction
    • Pneumothorax
  • Costs more than oral diets
  • Less palatable
  • Labor: 1) Intensive assessment, 2) Administration, 3) Tube patency and 4) Site care, monitoring.
12Methods of enteral nutrition (Table 1.9)
Complications of enteral feeding: 1) Access problems (e.g. tube obstruction), 2) Administration problems (e.g. aspiration pneumonia), 3) Gastrointestinal complications (e.g. diarrhea), 4) Metabolic complications (e.g. overhydration).
TABLE 1.9   Methods of enteral nutrition
Tube feeding less than 4 weeks
Tube feeding more than 4 weeks
  • Nasogastric
  • Nasoduodenal
  • Nasojejunal
  • Orogastric
  • Enterostomy
  • Gastrostomy
  • Jejunostomy
Rate and method of delivery*
  • Bolus: 300 to 400 mL rapid delivery via syringe several times daily
  • Intermittent: 300 to 400 mL, over 20 to 30 minutes, several times/day via gravity drip or syringe
  • Cyclic: via pump usually at night
  • Continuous: via gravity drip or infusion pump.
*Determined by medical status, feeding route and volume, and nutritional goals.
 
Parenteral Nutrition
Q. Write short essay/note on total parenteral nutrition.
  • Central access: Total pareneteral nutrition (TPN) both long- and short-term placement.
  • Peripheral parenteral nutrition (PPN).
Venous sites from which the superior vena cava may be accessed are subclavian vein, internal or external jugular vein, axillary vein, brachial vein, basilic vein and cephalic vein.
Advantages and disadvantages of parenteral nutrition (Table 1.10)
TABLE 1.10   Advantages and disadvantages of parenteral nutrition
Advantages
Disadvantages
  • Provides nutrients when less than 2 to 3 feet of small intestine remains
  • Allows nutrition support when GI intolerance prevents oral or enteral support
  • Economic impact
  • Time-consuming
  • Inconvenient
  • Disturbed sleep
  • Activities and work must be planned around feedings
Indications for total parenteral nutrition (Table 1.11)
TABLE 1.11   Indications for total parenteral nutrition
  • GI non functioning
  • Nil per oral (NPO) > 5 days
  • GI fistula
  • Acute pancreatitis
  • Short bowel syndrome
  • Malnutrition with >10% to 15% weight loss
  • Nutritional needs not met; patient refuses food
Complications of parenteral nutrition (Table 1.12)
TABLE 1.12   Complications of parenteral nutrition
Duration
Mechanical
Metabolic/GI
Infectious
First 48 hrs.
Malposition
Hemothorax/pneumothorax
Air embolism
Blood loss
Puncture of subclavian/carotid artery
Fluid overload
Hypoglycemia, Hypophosphatemia,
Hypokalemia, Hypomagnesemia
Refeeding syndrome
First 2 weeks
Catheter displacement
Thrombosis, air embolism
Occlusion
Hypoglycemic coma
Acid base and electrolyte imbalance
Catheter induced sepsis
Exit site infection
3 months onwards
Tear of catheter
Catheter thrombosis
Air embolism
Blood loss
Deficiency of: essential fatty acids, vitamins or trace element
Metabolic bone disease
Liver disease
Tunnel infection, Catheter induced sepsis
Exit site infection
13
 
Refeeding Syndrome
Definition: Refeeding syndrome is a syndrome consisting of metabolic disturbances that occur as a result of reinstitution of nutrition to patients who are starved or severely malnourished.
Time of occurrence: Usually occurs within 4 days of restarting nutritional support.
 
Mechanism
  • When nutritional support is given to a starved or severely malnourished patient, there is a rapid change from a catabolic to an anabolic state.
  • Administration of carbohydrates stimulates release of insulin. This causes cellular uptake of phosphate, potassium and magnesium and may lead to significant falls in their levels in the serum. This results in electrolyte imbalance and can produce serious consequences (e.g. cardiac arrhythmias).
 
Clinical Features
  • Initial features may be nonspecific.
  • Later: Rhabdomyolysis, leucocyte dysfunction, respiratory and cardiac failure, hypotension, arrhythmias, seizures, coma and sudden death.
  • Underdiagnosed and undertreated, but treatable.
 
PROTEIN-ENERGY MALNUTRITION
Protein-energy malnutrition (PEM) or protein-calorie malnutrition refers to a group of malnutrition where there is inadequate calorie or protein intake. Severe PEM is a serious, often lethal disease and usually affects children of low-income countries. PEM include marasmus, kwashiorkor and intermediate states of marasmus-kwashiorkor.
 
Marasmus
Q. Write short note on marasmus
  • Marasmus is the childhood form of starvation. It develops due to inadequate intake of protein and calories.
  • It is characterized by emaciation with obvious muscle wasting and loss of body fat. There is no edema. The hair is thin and dry. The marasmic child does not appear as apathetic or anorexic as with kwashiorkor. Diarrhea is frequent and there may be signs of infection.
 
Kwashiorkor
  • Inadequate protein intake: Kwashiorkor develops due to an inadequate protein intake with reasonable caloric (energy) intake.
  • Kwashiorkor occurs in a young child displaced from breastfeeding by a new baby. It is may be precipitated by infections (e.g. measles, malaria and diarrheal illnesses). Child appears apathetic and lethargic with severe anorexia.
  • Edema: In kwashiorkor, marked protein deprivation causes hypoalbuminemia leading to generalized or dependent edema.
  • Skin lesions: Children with kwashiorkor have characteristic skin lesions. This consists of alternating zones of hyperpigmentation, and hypopigmentation, producing ‘flaky paint’ appearance.
  • Hair changes: The hair is dry and sparse. There may be loss of color or alternating bands of pale and darker hair (Flag sign).
  • Other features: The other features that differentiate kwashiorkor from marasmus are:
    • Abdomen is distended due to hepatomegaly (presence of enlarged, fatty liver) and/or ascites.
    • Development of apathy, listlessness, and loss of appetite.
    • Likely presence of vitamin deficiencies.
    • Defects in immunity and secondary infections.
14Differences between Kwashiorkor and Marasmus are listed in Table 1.13.
TABLE 1.13   Differences between kwashiorkor and marasmus
Feature
Kwashiorkor
Marasmus
Definition
Inadequate protein intake with reasonable caloric (energy) intake
Inadequate intake of both protein and calories
Age
Children 6 months to 3 years
Infants under 1 year
Growth failure
Present
Present
Edema
Localized or generalized
Absent
Liver
Enlarged, fatty
Not enlarged
 
OBESITY
Q. Describe the risk factors, clinical features, complications and management of obesity.
Definition: Obesity is defined as an accumulation of excess body fat (adipose tissue) that is of sufficient magnitude to impair health. Latin word ‘obesus’ meaning stout, fat, plump.
Prevalence of obesity: Obesity is a major health problem in developed countries and an emerging health problem in developing countries, such as India.
TABLE 1.14   Classification of overweight and obesity by body mass index
Category
BMI kg/m2 (weight in kgs/height in meters)
Underweight
<18.5
Normal
18.5–24.9
Overweight
25.0–29.9
Obesity—Class I
30.0–34.9
Obesity—Class II
35.0–39.9
Extreme/morbid obesity—Class III
≥40
 
Classification of Overweight and Obesity by Body Mass Index (Table 1.14)
 
Types of Obesity According to Body Fat Distribution
The distribution of the stored fat is importance in obesity and accordingly obesity is divided into:
  • Central (‘abdominal’, ‘visceral’, ‘android’ or ‘apple-shaped’) obesity: This type of obesity shows increased accumulation of fat in the trunk and in the abdominal cavity/intra-abdominal (in the mesentery and around viscera). It is associated with a greater risk for several diseases (e.g. type 2 diabetes, the metabolic syndrome and cardiovascular disease) than generalized obesity.
  • Generalized (‘gynoid’ or ‘pear-shaped’) obesity: This type is characterized by excess accumulation of fat diffusely in the subcutaneous tissue.
 
Etiology
Q. Write short essay/note on causes of obesity.
Accumulation of fat in obesity can be considered by the result of caloric imbalance between the energy consumption (intake of calories) in the diet and energy expenditure through exercise and bodily functions. However, the pathogenesis of obesity is complex and incompletely known.
  1. Genetic aspects of human obesity:
    • Obesity is a polygenic disorder, with small contributions from a number of different genes.
    • Single-gene (monogenic forms) disorders are rare and produce severe childhood obesity. These include mutations in the leptin gene and leptin receptor gene, mutations of POMC (Proopiomelanocortin), Mc4R (melanocortin-4 receptor) genes.
    • A few genetic conditions in which obesity is a feature include the Prader–Willi and Laurence–Moon–Biedl syndromes.
  2. Environmental contributors to human obesity:
    • Food: Many environmental factors can influence food intake. Increased consumption of energy-dense foods, larger food portion size, and increased variety of food, increased availability, reduced cost and increased caloric beverages (soft drinks, juices) promote obesity.
    • Physical activity: It can be divided into three categories: (1) exercise (fitness and sports-related activities); (2) work-related physical activity; and (3) non-exercise, non-employment (spontaneous) activity. Increased sedentary behavior, reduced activities of daily living and decreased employment physical activity promote obesity.
  3. Reversible causes of obesity and weight gain:
    • Minority of patients presenting with obesity have specific cause which can be identified and treated (Table 1.15). Compared to idiopathic obesity, these patients have short history of marked weight gain.15
TABLE 1.15   Potentially reversible causes of obesity and weight gain
Endocrine factors
  • Hypothyroidism
  • Cushing's syndrome
  • Insulinoma
  • Stein-Leventhal syndrome
  • Hypothalamic damage (e.g. due to trauma, tumor)
Drug induced
  • Psychiatric and neurologic medications: Atypical antipsychotics (e.g. olanzapine) pizotifen, sodium valproate, flunarizine
  • Steroid hormones: Progestational steroids, corticosteroids, hormonal contraceptives
  • Anti-diabetes agents: insulin (most forms), sulfonylureas, thiazolidinediones
  • Antihypertensive agents:α-adrenergic and β-adrenergic receptor blockers
 
Pathogenesis (Fig. 1.2)
Body weight regulation (regulation of energy balance) or dysregulation depends on a complex interplay of both hormonal/endocrine and neural mechanism that control appetite and satiety. Neurohumoral mechanisms can be subdivided into three components.
 
1. Peripheral Afferent System
Peripheral afferent system can be further subdivided into peripheral appetite suppressing signals and peripheral appetite stimulant signals.
Peripheral appetite suppressing signals
  • Leptin (Greek term leptos, meaning ‘thin’.) Leptin is a hormone secreted by fat cells and it stimulates POMC/CART pathway (Fig. 1.3) and inhibits NPY/AgRP pathway and appetite is suppressed (anorexigenic). Increased leptin stimulates physical activity, heat production (thermogenesis), and energy expenditure.
  • Adiponectin: It is a hormone (fat-burning molecule) and the ‘guardian angel against obesity,’ and is produced mainly by fat cells (adipocytes). Its levels are lower in obese.
  • Resistin: Primarily produced by macrophages and not fat cells. It causes insulin resistance.
  • Gut hormones: These include PYY, pancreatic polypeptide, insulin, and amylin.
    • Insulin: It is secreted by cells of the pancreas and act centrally to activate the appetite suppressing pathway.
    • Peptide YY (PYY): It is secreted by the endocrine cells (L cells) in the ileum and colon. It reduces appetite. Other peripheral appetite suppressing signals include glucagon-like peptide 1 (GLP1) and oxyntomodulin.
    • Amylin: It is a peptide secreted with insulin from pancreatic β-cells.
Peripheral appetite stimulating signals
  • Gut hormones:
    • Ghrelin: It is produced by the oxyntic cells of the fundus of the stomach and in the arcuate nucleus of the hypothalamus. Ghrelin increases food intake (orexigenic effect) and stimulates appetite by activating the central appetite stimulating NPY/AgRP pathway.
      zoom view
      Fig. 1.2: Regulation of energy balance. Peripheral afferent system (appetite suppressing and stimulating signals) influences the activity of the hypothalamus, which is the central regulator of appetite and satiety. Signals from hypothalamus in turn act on peripheral efferent system (food intake and energy expenditure). See text for details.
    • 16Obestatin: It is a peptide produced by the same gene that encodes ghrelin. It counteracts the increase in food intake induced by ghrelin.
  • Retinol binding protein 4 (RBP4): Secreted by fat cells. Its actions counteract with those of insulin. Raised levels of RBP4 found in Type 2 diabetes mellitus.
 
2. Central Processing (Table 1.16)
zoom view
Fig. 1.3: Actions of leptin
The arcuate nucleus of the hypothalamus processes and integrates neurohumoral peripheral afferent signals and generates efferent signals. It consists of:
a) Central appetite suppressing (anorexigenic pathway or leptin melanocortin pathway)
  • In this pathway, POMC (pro-opiomelanocortin)/CART (cocaine and amphetamine-regulated transcripts) neurons enhance energy expenditure and weight loss through the production of the anorexigenic (suppresses appetite) neuropeptides mainly αMSH (α-melanocyte stimulating hormone) by cleavage of POMC by PC1 (prohormone convertase).
  • It exerts its appetite suppressing action via the activation of the melanocortin receptors 3 and 4 (MC3/4R) in second-order neurons.
  • Second order neurons in turn produce factors such as thyroid releasing hormone (TSH) and corticotropin releasing hormone (CRH) that increase the basal metabolic rate and anabolic metabolism, thus regulate food intake favoring weight loss.
b) Central appetite stimulating (orexigenic) pathway: It consists of:
  • NPY (neuropeptide Y)/AgRP (agouti-related peptide) containg neurons promote food intake (orexigenic effect) and weight gain, through the activation of Y1/5 receptors in secondary neurons.
  • Secondary neurons in turn release factors such as melanin-concentrating hormone (MCH) and orexin, which stimulate appetite. This pathway also decreases energy expenditure.
These pathways interact with each other and communicate with other parts of the brain, and influence the autonomic nervous system and ingestive behavior. These central pathways are in turn influenced by a variety of peripheral signals discussed above.
 
3. Peripheral Efferent System
It is organized into two pathways namely anabolic and catabolic that control food intake and energy expenditure, respectively.
Energy intake (Food intake)
  • Food: The increase in obesity can be related to the type of food consumed (i.e. food containing sugar and fat) and also psychological factors.
  • Control of appetite: Signals may affect different aspects of eating behavior. For example
    • Ghrelin (peptide produced by the stomach) increases hunger but does not affect satiation or satiety.
    • Cholecystokinin causes satiation, but has no effect on satiety.
    • Leptin act on multiple pathways, its deficiency causes increased hunger and reduced satiation and satiety.
  • Following a meal, substances such as cholecystokinin (CCK), bombesin, and glucagonlike peptide 1 (GLP1) are released from the small intestine, and glucagon and insulin from the pancreas. These hormones are involved in the control of satiety. The control of appetite is extremely complex. Many transmitters in the central nervous system affect appetite:
    • Appetite inhibitors: dopamine, serotonin, γ-aminobutyric acid
    • Appetite stimulators: e.g. opioids
    • Regulation of food intake by central nervous system (Table 1.16).
TABLE 1.16   Examples of central nervous system regulators of energy balance
Central anabolic (increased intake) regulators
Central catabolic (decreased intake) regulators
Neuropeptide Y
α-Melanocyte-stimulating hormone
Agouti-related protein
Corticotropin-releasing hormone
Melanin-concentrating hormone
Thyrotropin-releasing hormone
Hypocretins and orexins
Cocaine- and amphetamine-regulated transcript (CART)
Energy expenditure
It can be divided into resting (or basal) metabolic rate, the thermic effect of food, and physical activity energy expenditure.
  • Resting basal metabolic rate (BMR): BMR is the energy expenditure and accounts for about 70% of daily energy expenditure, whereas active physical activity contributes to 5–10% of energy expenditure.
  • 17Thermic effect of food (thermogenesis): About 10% of ingested energy is spent in the process of digestion, absorption, and metabolism of nutrients irrespective of physical activity. This is called as dietary induced thermogenesis which is lower in obese and post-obese individuals.
  • Physical activity: Obese individuals tend to spend more energy during physical activity as they have a larger mass to move.
 
Pathologic Consequences of Obesity (Complications of Obesity)
Q. Write short essay/note on complications of obesity.
Morbidity and mortality: Obesity is associated with an increase in mortality and morbidity. Obese individuals are at risk of early death, mainly from diabetes, coronary heart disease and cerebrovascular disease.
 
Metabolic Complications of Obesity
Central obesity or upper body fat distribution is associated with increased concentration of FFA (free fatty acid) which can produce several metabolic complications of obesity.
Insulin resistance and type 2 diabetes mellitus
  • Insulin resistance is the decrease/failure of target (peripheral) tissues to insulin action. Insulin resistance can develop in obesity and may produce type 2 diabetes mellitus. Central/upper body/visceral obesity are found in more than 80% of patients with type 2 diabetes.
  • Causes of insulin resistance in obesity:
    • Obese individuals have excess circulating free fatty acids (FFAs) and there is an inverse correlation between fasting plasma FFAs and insulin sensitivity. Central obesity is associated with insulin resistance. Excess intracellular FFAs increases gluconeogenesis.
    • Adipokines: Adipose tissue acts as a functional endocrine organ and secrets variety of proteins into the systemic circulation, which are termed adipokines (or adipose cytokines). In obesity, adiponectin (one of the adipokines) levels are reduced, which contributes to insulin resistance.
  • Consequences of insulin resistance (Box 1.4)
Dyslipidemia
  • Upper body obesity and type 2 diabetes mellitus are associated with an atherogenic lipid profile. Dyslipidemia includes increased triglycerides, increased low-density lipoprotein (LDL) cholesterol with very low density lipoprotein (VLDL) cholesterol, decreased high-density lipoprotein (HDL) cholesterol, and decreased levels of the vascular protective adipokine adiponectin.
  • Dyslipidemia increases the risk of cardiovascular diseases (atherosclerosis, cardiomyopathy) in the metabolic syndrome (Fig. 1.4).
 
Endocrine Manifestations of Obesity
Reproductive disorders associated with obesity are listed in Table 1.17.
 
Mechanical Complications of Obesity
Q. Write short essay/note on mechanical complications of obesity.
  • Osteoarthritis: Excessive body weight in obesity predisposes to increased prevalence of lower extremity degenerative joint disease (osteoarthritis) and also gout.
  • Venous stasis/varicose veins
  • Acanthosis nigricans: It manifests as darkening and thickening of the skinfolds on the neck, elbows, axilla and dorsal interphalangeal spaces. It reflects the severity of underlying insulin resistance.
    zoom view
    Fig. 1.4: Obesty and metabolic syndrome
  • 18Increased friability of skin: It may be seen especially in skinfolds, thereby increasing the risk of fungal and yeast infections.
  • Urinary incontinence
TABLE 1.17   Endocrine manifestations of obesity
Men
Women
  • Plasma Testosterone and SHBG are reduced
  • Increased androgen
  • Increase Estrogen
  • Decrease SHBG
  • Gynecomastia seen
  • PCOS
  • Secondary sexual characters preserved
  • Not only fertility but their chances of IVF success reduces
Abbreviation: SHBG = Sex hormone-binding globulin; PCOS = Polycystic ovary syndrome.
 
Pulmonary Disease
  • These include reduced chest wall compliance, increased work of breathing, increased minute ventilation (due to increased metabolic rate), and decreased functional residual capacity and expiratory reserve volume.
  • Obstructive sleep apnea: Sleep apnea is common in patients with severe obesity. Sleep apnea can be obstructive (most common), central, or mixed and is often associated with an increased risk of hypertension, right heart failure and sudden death.
  • Obesity and asthma: Reduced TLC (total lung capacity), reduced RV (residual volume) and FRC (functional residual capacity).
TABLE 1.18   Obesity and related cancers
Males
Females
Esophagus
Gallbladder
Colon
Bile ducts
Rectum
Breasts
Pancreas
Endometrium
Liver
Cervix
Prostrate
Ovaries
 
Obesity and Cancer (Table 1.18)
  • Obesity is the biggest preventable cause of cancer after smoking. Accounts for 14% of cancer deaths in men and 20% in women.
 
Gastrointestinal Disorders
Following are more prevalent in obese patients:
  • Gastroesophageal reflux disease
  • Gallstones: Obesity is associated with increased secretion of cholesterol in the bile, super saturation of bile, and a higher incidence of gallstones, especially cholesterol gallstones.
  • Fatty liver (steatosis) and nonalcoholic steatohepatitis (NAFLD): NAFLD can progress to hepatic cirrhosis and rarely to hepatocellular carcinoma.
 
Obesity and Retinal Disease
  • Overweight diabetics are twice more likely to develop retinopathy than non obese.
  • Waist to hip ratio was only second to glycemic control in its importance in preventing retinopathy in studies.
Conditions and complications associated with obesity are summarized in Table 1.19.
 
Clinical Assessment, Investigations and Diagnosis
Aims of assessing of obesity is to:
  1. Evaluate and severity of obesity: Severity of obesity can be quantified using the BMI (Table 1.14).
  2. Exclude an underlying cause
  3. Identify complications
  4. Prepare a management plan
Q. Write short essay/note on diseases for which obesity is a risk factor.
TABLE 1.19   Conditions and complications associated with obesity
Risk factors/system involved
Outcomes
Metabolic syndrome
  • Type 2 diabetes
Coronary heart disease, Ischemic heart disease
  • Hypertension
Stroke
  • Hyperlipidemia
Diabetes complications
Cardiovascular
Heart failure
Gastrointestinal
Gastroesophageal reflux disease
Hiatus hernia19
Hepatobiliary
Liver fat accumulation
Nonalcoholic steatohepatitis
Cirrhosis
Gallstones
Pulmonary disease
Restricted ventilation
Exertional dyspnea, breathlessness
Obstructive sleep apnea
Obesity hypoventilation syndrome (Pickwickian syndrome)
Mechanical effects of weight
Urinary incontinence
Osteoarthritis of knees and hips
Varicose veins
Back strain
Endocrine manifestations
(Increased peripheral steroid interconversion in adipose tissue)
Menstrual abnormalities
Hormone-dependent cancers (breast, uterus)
Polycystic ovarian syndrome (infertility, hirsutism)
Increased morbidity and mortality
Psychological problems
Lack self confidence, depression, more physical and sexual abuse, lack of attention, low education, and low self-esteem
Others
Accident proneness
Socioeconomic disadvantage (lower income, less likely to be promoted)
Postoperative problems
Increased cancer risk (e.g. colorectal cancer)
Skin infections (groin and submammary candidiasis; hidradenitis)
Q. Write short essay/note on management of obesity.
 
ENVIRONMENTAL DISEASES
 
Radiation Exposure
 
Types of Radiation
They are divided into two types:
  • Ionizing radiation: Used in X-rays, computed tomography (CT), radionucleotide scans and radiotherapy. Radiations interact with atoms, and release energy and results in ionization which can cause molecular damage.
    • Penetrating radiation: It includes uncharged neutrons or high-energy electromagnetic radiations such as X-rays and gamma (γ) rays. It affects the skin and deeper tissues.
    • Nonpenetrating radiation: It includes charged subatomic alpha (α) and beta (β) particles.
  • Non-ionizing radiations: Ultraviolet (UV) rays of sunlight visible light, laser, infrared and microwave. It affects only skin. Non-ionizing UV is used for therapy in skin diseases and laser therapy for diabetic retinopathy.
 
Dosage and Exposure
  • Dosage: The dose of radiation depends on the energy absorbed by a unit mass of tissue. It is measured in joules per kilogram (J/kg); 1 J/kg = 1 gray (1 Gy) = 100 rads.
  • Radioactivity:
    • It is measured in becquerels (Bq). 1 Bq is defined as the activity of a quantity of radioactive material in which one nucleus decays per second; 3.7 × 10 Bq = one curie (Ci) (older terminology was non SI unit).
    • To take account of different types of radiation and variations in the sensitivity of various tissues, weighting factors are used to produce a unit of effective dose. Therefore, for measurement a dose equivalent called a sievert (Sv) is used. Sv value reflects the absorbed dose weighted for the damaging effects of a particular type of radiation and is most useful in evaluating the long-term effects of radiation exposure.
  • Background radiation: It is exposure of humans to naturally occurring radioactivity (e.g. radon gas and cosmic radiation). Average annual background radiation is about 2.5 mSv per year (varies according to local geology). A chest X-ray delivers 0.02 move, and CT of the abdomen/pelvis about 10 mSv.
 
Effects of Radiation Exposure
Q. Write short essay/note on effects of radiation exposure.
Excessive exposure to ionizing radiation: It may occur accidently in industry, nuclear power plants and hospitals. It may be also due to deliberate nuclear explosions designed to eliminate populations and rarely by poisoning, e.g. with polonium.
  • Radiation sickness:
Q. Write short note on radiation sickness.
  • Mild acute radiation sickness: It is characterized by nausea, vomiting and malaise follow doses of about 1 Gy lymphopenia develops within several days, followed 2–3 weeks later by a fall in all WBCs and platelets.
  • Acute radiation sickness: It involves several systems and the extent of damage depends on the dose of radiation. Commonly involved systems are hematopoietic, gastrointestinal, central nervous system and skin.
  • Effects on the individual are classified as either deterministic or stochastic.
Deterministic (threshold) effects
  • Intensity of exposure: Radiation effects depend on the type of radiation, the distribution of dose and the dose rate. The severity of deterministic effects is proportional to the dose of radiation above a threshold level.
  • Tissue vulnerability:
    • Tissue with labile cells: Tissues with actively dividing cells (labile cells), such as bone marrow and gastrointestinal mucosa, are more sensitive to ionising radiation.
    • Hemopoietic system: Lymphocyte depletion is the most sensitive indicator of bone marrow injury and after exposure to a fatal dose, marrow aphasia is a commonest cause of death.
    • Gastrointestinal mucosal toxicity: May cause death due to severe diarrhea, vomiting, dehydration and sepsis.
    • Gonads: Highly radiosensitive and may cause temporary or permanent sterility.
    • Eye: Cataracts.
    • Skin: Radiation dermatitis (radiation burns) characterized by skin erythema, purpura, blistering and secondary infection may occur. Complete loss of body hair develops after an exposure > 5 Gy.
    • Lung: Acute inflammatory reactions, pulmonary fibrosis.
    • Central nervous system syndrome: Exposures of >30 Gy are followed rapidly by nausea, vomiting, disorientation and coma. Death due to cerebral edema can follow within 36 hours. It may also cause permanent neurological deficit.
    • 22Bone necrosis and lymphatic fibrosis occur following regional irradiation, particularly for breast cancer.
    • Thyroid gland due to its capacity to concentrate iodine is responsible for its susceptibility to damage even after exposure to relatively low doses of radioactive.
Stochastic effects
Stochastic (chance) effect is directly proportional to the dose of radiation.
  • Carcinogenesis: It represents a stochastic effect. With acute exposures, leukemias (e.g. acute myeloid leukemia) may develop after a latent period of 2–5 years and solid tumors (e.g. skin, thyroid and salivary glands) after a latent period of about 10–20 years. Thereafter the incidence of cancer increases with time. Cancer risk depends on the amount of radiation received, the time to accumulate the total dose and the interval following exposure.
  • Teratogenic effects.
 
High Altitude
 
Physiological Effects of High Altitude
  • In high altitude, the proportions of oxygen, nitrogen and carbon dioxide in air do not change but their partial pressure falls in proportion to barometric pressure.
  • At high altitude, oxygen tension is reduced within the lung alveoli. This result in a fall in arterial oxygen saturation.
 
Illnesses at High Altitude
Q. Write short essay/notes on mountain sickness.
Ascent to altitudes up to 2500 m or travel in a pressurized aircraft cabin is harmless to normal individuals. Above 2500 m high-altitude illnesses may develop in healthy individuals, and above 3500 m these commonly develop. Sudden ascent to altitudes above 6000 m (e.g. by aviators, balloonists and astronauts), may cause decompression sickness with the clinical features similar to in divers, or even loss of consciousness. However, most high altitude illness develops in travellers and mountaineers.
Acute mountain sickness (AMS)
Acute mountain sickness is a syndrome characterized by headache, fatigue, anorexia, nausea and vomiting, difficulty sleeping or dizziness. Ataxia and peripheral edema may be present.
  • Etiology: Not fully understood. Probably hypoxemia increases cerebral blood flow and intracranial pressure.
  • Symptoms: Develop within 6–12 hours of an ascent and vary in severity from trivial to completely incapacitating.
Chronic mountain sickness (Monge's disease)
  • It occurs on long exposure to high altitude.
  • Symptoms: Headache, poor concentration and signs of polycythemia.
  • Physical examination: Cyanosis and clubbing of fingers.
High-altitude cerebral edema (HACE)
  • High-altitude cerebral edema is a rare, life-threatening condition and usually proceeded by AMS.
  • Symptoms: Ataxia and altered consciousness. In addition to features of AMS, the patient also develops confusion, disorientation, visual disturbance, lethargy and can lead to loss of consciousness.
  • Signs: Papilledema and retinal hemorrhages are common. Focal neurological signs may be detected.23
High-altitude pulmonary edema (HAPE)
Q. Write short essay/notes on high altitude pulmonary edema.
  • High-altitude pulmonary edema is a life-threatening condition.
  • Time of occurrence: It usually occurs in the first 4 days after ascent above 2500 m. Unlike HACE, HAPE may develop de novo without the preceding signs of AMS.
  • Symptoms:
    • Initially, dry cough, exertional dyspnea and extreme fatigue. Later, the cough becomes wet and may be with blood-stained sputum.
    • Tachycardia and tachypnea develop at rest. Crepitations may be heard in both lung fields. It may lead to severe hypoxemia, pulmonary hypertension.
  • Investigations:
    • Radiologically show diffuse alveolar edema.
    • Decreased arterial oxygen saturation.
High-altitude retinal hemorrhage
It may be found in about 30% of trekkers at 5000 m and is usually asymptomatic and resolve spontaneously. Visual defects can develop when the hemorrhage involves the macula. There is no specific treatment.
Venous thrombosis
Can develop at altitudes over 6000 m. Risk factors are dehydration, inactivity, cold and use of oral contraceptive pill at high altitude.
Refractory cough
Cough is common at high altitude and usually benign. Causes include breathing of dry, cold air and increased mouth breathing. It may be similar to cough that occurs in early HAPE.
 
Lathyrism
Q. Write short note on lathyrism.
Lathyrism is a paralyzing disease caused by eating seeds of Lathyrus sativus (khesari dal).
Epidemiology: It is prevalent mostly people in India (e.g. Madhya Pradesh, Uttar Pradesh, Bihar and Orissa), Bangladesh, Pakistan, Nepal and Algeria.
Etiology: Lathyrus sativus (khesari dal) is a good source of protein. It is relatively cheap pulse and is consumed mostly by the poor agricultural laborer. But it contains L-ODAP (β-N-oxalyl-l-α-diamino propionic acid) also called β-N-oxalyl-amino-L-alanine, or BOAA, which is an excitatory neurotoxin and glutamate agonist. If the diets containing more than 30% of this dhal is consumed over a period of 2 to 6 months will produce lathyrism.
Clinical features: Affects mainly young males between 15 to 45 years of age. In humans it mainly affects nervous system and is called neurolathyrism which produces pure motor spastic paraplegia. Sensations and sphincters are preserved.
 
Stages
  • Latent stage: Patient appears healthy but when subjected to physical stress exhibits ungainly gait. If the disease is recognized at this stage, age, withdrawal of pulse from the diet will result in complete remission of disease.
  • No-stick stage: During this stage, the patient walks with difficulty having short jerky steps but does not need the aid of a stick.
  • One-stick stage: The patient walks with a crossed gait with a tendency to walk on toes and develops musculoskeletal stiffness. Use of a stick is necessary to maintain balance.24
  • Two-stick stage: Symptoms are more severe at this stage. Due to excessive bending of the knees and crossed legs, the patient requires support by two crutches for support. The gait is slow and clumsy and complains of easy tiredness after walking a short distance.
  • Crawler stage: Finally spastic paralysis develops which becomes irreversible. It becomes impossible to maintain erect posture as the knee joints cannot support the weight of the body. The thigh and leg muscles become atrophied and patient crawls by throwing his weight on his hands.
 
Prevention
  • Vitamin C prophylaxis 500–1000 mg for a week
  • Banning the crop if possible
  • Removal of toxin:
    • Steeping method: Soaking the pulse in hot water for 2 hours and the soaked water is drained off completely. The pulse is washed again with clean water and then drained off and dried in the sun. There will be loss of vitamins and minerals by this method.
    • Parboiling: Suitable for large scale operation and is similar to parboiled rice. It destroys trypsin inhibitors.