Dermoscopy: Text and Atlas Subrata Malakar, Purva Mehta, Priya Diwaker, Samipa S Mukherjee, Sushrut Save, Anjali Pal, Surit Malakar
INDEX
Page numbers followed by b refer to box, f refer to figure and t refer to table
A
Acetowhite test 153
Achromic/hypochromic lesion 165
ACLE See Acute cutaneous lupus erythematosus
Acquired immunodeficiency syndrome 405
Acute cutaneous lupus erythematosus 260
Adnexal openings, nonpigmented 61f
Allergic contact dermatitis 135f
Alopecia
over scalp, diffuse nonscarring 299f
patches of 168f
Anetoderma 419
Angiokeratoma 399
diagnostic of 417, 418
solitary 27f
Angioma serpiginosum 27, 401, 401f
Annular brown pigmentation, peripheral 131f
Apple-Jelly sign 313
Arthroconidia 168
Ash leaf macule 342
Atrophic scars 406
white 407f
Atrophy, epidermal 285f
Auspitz sign 2, 132, 455
dermoscopic 132, 138f140f, 461, 462f
Autoimmune disorder 287
B
Basal cell carcinoma 38f, 43, 56f, 63, 64f, 80f, 239, 242f, 244f, 415, 416f, 435, 435f, 460
arborizing vessels, non-pigmented 38f
diagnostic of 415
nodular 25f
noduloulcerative pigmented 244f
nonpigmented 248
pigmented 239, 242f
Basaloid cells 40
nests of 416f
Becker melanosis 358
Becker's nevus 358, 358f
dermoscopic features of 358f
Becker pigmentary hamartoma 358
Black lamella 447
Blisters 260
Blood spots 257, 258f
central 415
Blue nevus 15f
Blue-gray
blotches 40, 40f
dots/globules 239, 241f
ovoid nests 40, 239, 240f, 246f
Blue-white veil 16, 41
Borderline tuberculoid leprosy 344, 344f
Bowen's disease 53f, 182, 183f
Bowenoid papulosis 153
Brain-like
appearance 42
structures 208b
Brown amorphous area 445
Brown black follicular plugging 443
Brown dots and globules 423f
Bullous pemphigoid 125f
Burning sensation over face 172f
Butterfly rash 296f
C
Calcineurin inhibitors 172f
Callus 85
dermoscopy of 159f
Capillary loss 264, 265f
Capillary malformations 380, 389
Central homogeneous pigmentation 459f
Central keratin 257, 258f
vessels 413f
Central keratotic plug 366
Central white
network 189f, 191f
scar-like
area 79f
patch 188f, 189f
structure 196f
Cerebriform pattern 42, 207
Cheilitis ulcers 260
Chromophore hemoglobin 75
Classic white scar-like patch 190f
Clavus 85
Clear cell acanthoma 22f, 53
CLOs See Comedo-like openings
Cloudy sky pattern 230, 231f
CMN See Congenital melanocytic nevi
Cobblestone pattern 44, 223f
Collarette scaling, typical 129f, 131f
Colloid milium, pigmented 350
Comedo-like
openings 45, 207, 208b, 209f, 210f, 211f, 212f, 279f, 281f
structures 195f
Comma hairs, multiple 169f, 185f
Comma vessels 46, 46f, 318f, 319f
Complete delicate pigment network 187f, 188f
Complete pink-brown homogeneous dermatofibroma 198f
Complete white
network pattern 190f
scar-like patch 191
Condylomata lata 153
Congenital melanocytic nevi 80f, 358
Contact dermatitis, pigmented 353
Corn revealed central core, superficial paring of 160f
Cosmetic dermatitis, pigmented 353, 354f
Cribriform, progressive 421
Crown vessels 47
Crystalline structures 43
Cuboidal epithelial cells 36f, 232f
Cutaneous sclerosis, plaques of 287
Cystic
dilatations 226
lesions, vessels-free 227
Cysts
dermal 227
keratinous 235
milia-like 195f, 207, 208b, 211f, 235, 236f, 461f
D
Darier's disease 359
Darier-White disease 359
De novo melanoma, developing 447
Deep perivascular lymphocytic infiltrate 312f
Demodex
brevis 172
folliculorum 172, 254, 255f, 256f, 316f
mites, high density of 172
tails of 172, 467f
white spicules of 175f, 467f
Demodicosis 172
Dermal fibrocytes, number of 185
Dermal fibrosis, diffuse 34f
Dermal-epidermal junction 347
Dermatitis 95
stasis 53
Dermatofibroma 43f, 79f, 185, 186t, 190f, 192f, 195f
central seborrheic keratosis like 194f
dermoscopic patterns of 186t
multicomponent pattern of 192f
Dermatomyositis 264, 264f
Dermatoscope 4
application of 182
Dermatoscopy 2, 5
Dermatoses 419
annular 114f
autoimmune 260
granulomatous 302
infectious 148
papulosa nigra 148
Dermis, superficial 382f
Dermoepidermal junction 14, 15, 48, 65
Dermoscope 4, 58f
components of 4
achromatic lens 4
inbuilt illuminating system 4
power supply 4
working principle of 4
Dermoscopic dialogues
blotches 39
blue-gray blotches 40
blue-white veil 41
cerebriform pattern 42
chrysalis structures 43
cobblestone pattern 44
comedo-like openings 45
comma vessels 46
crown vessels 47
dots 48
dotted vessels 49
fingerprint-like structures 52
fingers 51
globules 52
glomerular vessels 53
lacunae 55
leaf-like areas 56
melanocytic network 56
milia-like cysts 58
moth-eaten border 59
multicomponent pattern 59
negative pigment network 60
peppering 60
polymorphous vessels 62
pseudonetwork 61
regression structures 62
reticuloglobular pattern 63
spoke-wheel structures 63
starburst pattern 64
streaks 65
structureless areas 66
twisted red loops 67
Wickham striae 68
Wobble sign 69
Dermoscopic structures
cobblestone pattern 15
dots and pigmented globules 14
homogeneous pigmentation 15
multicomponent pattern 16
parallel pigment pattern 13
pigment network 11
streaks 15
Dermoscopy 1, 2, 6, 44f, 83f, 132, 167f, 212f, 216f, 252f, 265f, 270f, 296f, 297f, 326, 333, 346, 362f, 378f, 391f, 406, 445, 465f
cloudy sky pattern 35
demonstrates
diffuse pigmentation 120f
ivory-white homogeneous 234f
highlights color of tattoo 430f
jet black color 90t
melanocytic patterns 11
nails 299f
non-polarized 93
notable patterns 29
orange hue 90t
palisade pigmentation pattern 30
polarized 93
preliminary groundwork 18
rainbow pattern 92
red starburst pattern 34
red/pink hue 90t
vascular patterns 18
wet and dry 6
white shiny structures 79
white starburst pattern 29
yellow and orange color 85
Diabetes mellitus 318, 319f
Dirty dermatoses, group of 444
Discoid eczema 461
Discoid lupus erythematosus 30f, 34f, 64, 267, 268f, 270f, 295
advanced lesion of 269f
Dotted vessels 22f, 49, 96f
Drug hypersensitivity reactions 441
Dyskeratosis 368f
Dyspareunia 379f
Dysplastic nevi 64, 447, 448
multicomponent 448
E
Eccrine
hidrocystoma 227
poroma 53
sweat duct 227
Ectothrix parasitization 169f
Ectothrix tinea capitis 168
Eczema
discoid 456
nummular 85
Endothrix fungus infection 168f
Epidermal hyperplasia, mild 216f
Epidermal keratinization, disorder of 374
Epidermis 185
protrusions of 51
Epithelioid cells 307f
Erosions 260
Erythema 102f, 311f
generalized 302
mild 446f
multiforme 425
lesion, classical 425f
peripheral 399
Erythematous
annular
lesions 308f
plaque 462f
brownish macules over trunk 446f
excoriated papules, multiple 178f
hue 77f
macules 260f
papular rash on arms 260
papule 260f, 366, 382f
plaque
and scaling 135f
slow growing 183f
Erythrocyte 404f
extravasation 401
perifollicular extravasation of 268
Erythroplasia of Queyrat 153
Exophytic papillary pattern 221f
F
Facial
erythema 264f
hairs
infundibulum of 467f
trichoscopy of 173f
lesions 61f
pigmentary demarcation line, dermoscopy of 353f
Fascia 292f
Fat fingers 51f, 213f
like structures 213f, 214f
Favre-Racouchot syndrome, part of 443
Fibrotic beams 287, 290f
dermoscopy reveals 288f
Fine short linear vessel 255f
Finger-like
pattern 153
projections 152
Fingerprint-like structures 208b, 214f, 215f, 423f
Fissures 138f
multiple 42f
Flat topped skin-colored papules, multiple 236f
Follicular plugging 270f, 273f, 285f, 297f
dermoscopy reveals 270f
prominent 275f
Follicular red dots 268
Follicular sparing 354f
Fordyce's spots 427
Fungal
hyphae 168
infection 168
G
Genital
lesions 154f
dermoscopy of 329f
lichen sclerosus et atrophicus 327f
pyogenic granuloma 154f
warts, dermoscopy of 154f
Genitalia, male 115f
Giant cells 307f
Glans penis 104f
Globules, peripheral 447
Glomerular vessels 26f, 53f, 182, 408f, 409f
patchy distribution of 183f
Glucose transporter-1 380
Granuloma annulare 308, 310f
Granulomatous diseases 85
Greasy brown papules over seborrheic areas 360f
Grover's disease 366
Guttate hypomelanosis, idiopathic 321, 322, 450
Guttate psoriasis 142f, 143f
Gyri of brain 42f
H
Hailey-Hailey disease 362, 468f
dermoscopy of 372f
Hairpin vessels 23, 24f, 54f, 152, 207, 208b, 221f, 385f
peripheral 413f
Hairs
block 168
broken 168
casts 168
comma 168, 169f
corkscrew 168, 169f, 171f
density, loss of 471f
follicles 185, 447
targetoid 257, 433
loss, diffuse 470f
Hairy epidermal nevus, pigmented 358
Hairy melanocytic nevus 458
Hemangioma 1, 27
lobular capillary 383
Hemorrhage 464f
cuticle 264, 265f
focal 208b
Hemorrhagic crust 399, 401
central 403f
Hemosiderotic hemangioma, targetoid 406
Herniated saclike skin 419
Hidrocystoma, apocrine 226
Highly polymorphous vascular structures 257
Histiocytes 307f
Homogeneous
blue pigmentation 15f
brown-gray pigmentation 185f
opacity 159f
Honeycomb pattern 57f
Human hair follicle 172
Hygroma, cystic 394, 395f
Hyperchromatic nuclei 416f
Hyperglobulinemic purpura 441
Hypergranulosis 464f
Hyperkeratosis 110f, 274f, 302, 464f
orthokeratotic lamellated 217f
Hyperkeratotic annular plaque 376f
Hyperkeratotic itchy plaque 122f
Hyperpigmentary disorders 6
Hyperpigmentation 346
grayish homogeneous 424
Hyperpigmented lesion, slow growing 460
Hyperpigmented plaque 103f
asymptomatic 288f
Hyperplasia, epidermal 34f, 216f, 220f
Hypertrophic lesions, dermoscopy of 113f
Hypopigmentary disorders 6
dermoscopy of 321
Hypopigmented patch 427f, 440f
Hypopyon-like structures 397f
I
Iceberg pattern 369f
I-hairs 168, 170f
Infantile hemangioma 380, 381f
precursors 381
Infectious skin diseases, diagnosis of 148
Interstitial lymphocytic infiltrate 292f
Itchy lesions over left foot, moderately 109f
Itchy plaque 122f
Ivory white areas 407
J
Juvenile xanthogranuloma 35, 85, 89f, 431
K
Kaposi's sarcoma 92, 405
Keratin
crusts 415
cysts 237f
dermoscopically 257
Keratinization, disorders of 359
Keratinocytes, degeneration of 437
Keratoacanthoma 23, 53, 203, 205f, 257
diagnosis of 412
Keratosis 153
follicularis 359
pits and punctate 361f
Keratotic halos 149f
Keratotic papules and plaques, hyperpigmented 452f
Knoblike patterns 153
L
Lacunae 21t, 27, 403f
blood filled 55f
dark 399
dermoscopy reveals 401
groups of 403f
red 397f, 398f, 399
yellow-white 397f, 407, 410f
Langhans giant cells 318f
Large white keratotic halos 464f
Late discoid lupus erythematosus 270f
Leishmaniasis, cutaneous 302
Leprosy 344
Lesions
after Grattage test 167f
caviar-like 350
cover surface of 218f
depigmented 333
dermoscopy of 376f, 436f
early 267
granulomatous 85
hyperkeratotic nature of 110f
hypertrophic 113f
hypopigmented 337, 344
long-standing 267
multiple annular 378f
non-melanocytic 54
papular 113f, 205f
reveals hyperpigmented border 457f
vascular morphology of 1
vitiliginous 333
Leukocytoclastic vasculitis 441
Lichen plano pilaris 470f
Lichen planus 68f, 97, 99f, 104f106f, 111f, 112f, 122f, 153
annular 115f, 466f
background color 98b
blisters develop atop lesions of 125f
classical 101f
dermoscopic features 97
dermoscopy of 465f
hyperkeratotic 111f
hypertrophic 32f, 112f, 452
lesions of 122f, 467f
like keratosis 218f
linear 118f, 119f
mucosal 102f
oral 103f
pemphigoides 125f
pigment patterns of 98b
pigmentosus 121f, 355, 355f
inversus 355
plaque of 102f
special patterns 98b
vascular patterns of 98b
Lichen sclerosus 278
et atrophicus 326
extragenital 85, 284f
Lichen simplex 109f, 122f
chronicus 452
Lichenoid interface vacuolar dermatitis 285f
Lichenoid lymphocytic infiltrate 285f
Lichenoid papules 121f
typical 121f
Lichenoid reaction, tattoo ink-induced 430
Light emitting diodes 4
Limbs, flexural surfaces of 99f
Linear
branching vessels 278, 287, 325f
pigmentation 106f
Wickham's striae 106f
Lips, vermillion border of 427
Livedoid vasculopathy 406, 407f
advanced stage of 410f
dermoscopy of 408f
Lobules, yellow-white 228f
Lower epidermis/dermoepidermal junction 71f
Lupus
erythematosus, cutaneous 260
miliaris disseminatus faciei 433
sarcoidosis 344
vulgaris 313, 344, 434f
Lustre, mica-like 218f
Lymphangioma 395f
cavernous 394, 395f
circumscriptum 394, 395f
cutaneous 85, 394
dermoscopy of 89f
Lymphatic malformations 380
Lymphatic system, anomalies of 395f
Lymphocytes
deep perivascular infiltrate of 263f
granuloma consists of 307f
lumps of 254
M
Macular lesions, depigmented 451f
Malar eruption 260
Maple leaf-like structures 239, 240f, 246f
Mastocytosis, cutaneous 85, 445
Melanin
dermoscopic color detection of 70
laden melanocytes 41
module 70, 71f, 73f
concept of 71
Melanocytes 12f, 185
number of 321
Melanocytic
hamartoma, dermal 356
lesion 14f, 54, 346
neoplasm 393, 394f
network, normal 12f, 57f
nevi, congenital 80f
nevus 44f, 73f, 74f, 212f, 333, 406, 458
compound 46f
patterns 11
proliferations, benign acquired 447
Melanoma 25, 43, 448, 449b
Melanophages 41
Melanosis, frictional 444
Melasma 348, 350t
area severity index 5
dermal 350
epidermal 348, 350
mixed 350
ochronosis 350
treatment, complication of 348
types of 350
Mica-like structures 208b, 218f
Microcystic lymphatic malformation 396f, 397f
dermoscopy of 395f
Microsporum 168
canis 168
Milia 39f, 85, 435
diagnosis of 435
multiple large and small 58f
Milky white macules, multiple 327f
Mimics dermatofibroma 406
Molluscum contagiosum 24f, 161, 161f, 162f, 163f, 164f, 411
lesions 81f
Morphea 287
superficial 287, 289f
Morse code hairs 168, 170, 170f
Moth-eaten border 59f, 207, 208b, 209f
Mycobacterium tuberculosis 313
Mycosis fungoides 254
early 441
Myxoid stroma 383
N
Nasal ala 434f
Necrobiosis lipoidica 318
Neonatal prematurity 419
Neoplasms, benign 218f
Nevus depigmentosus 330, 331f
white patch of 331f
Nevus of Ota 356, 357f
Nevus
compound 411
conventional junctional 39
epidermal 378f
Nits on hair shafts, multitude of 176f
Nodular tuberculoid granulomatous inflammation 307f
Nodule
hyperpigmented 242f
solitary 112f
Normal facial skin, dermoscopy of 347, 347f
Notalgia paresthetica 82f, 437, 438f
O
Oceanic corals, tentacles of 27
Ochre-colored pigment 350
Ochronosis, exogenous 350
Opaque brown pigmentation 208b
Oral retinoids 371f, 469f
P
Pale yellow globules, clouds of 431f
Palisade pigmentation 30f, 273f, 275f
pattern 30
Palm enhances pits and punctate keratosis, dermoscopy of 465f
Panniculitic morphea 392f
Papillary dermis 14, 40, 51, 156, 256f
melanin in 71f
Papillomatosis 464f
Papules 304
purpuric 406
Papulonodule 435f
Papulosquamous disorders 95, 474
Parallel pigment pattern 13f
Patchy alopecia 169f
Patchy nodular tuberculoid granulomatous 318f
Pearls, string of 49
Pediculosis capitis 176
infestation of 176
Pediculus humanus var capitis 176
Pemphigus, familial benign 367
Penicillamine 419
Periappendageal lymphohistiocytic infiltrate 294f
Perifollicular pigmentation 324f, 335f
Perilesional pigment
network 336f
prominent 325f
Peripheral delicate pigment 201f
network 189f, 191f
Peripheral homogeneous pigmentation 198f
Peripheral reticular
melanocytic network 459f
with central
globules 447
hypopigmentation 447
Photosensitivity 260
Pigmentary
demarcation line 352, 353f
dermatosis, acquired 356
disorders 321, 346
incontinence 83f
Pigmented lesions, dermoscopy of 346
Pigmented patches over bilateral lower limbs 441f
Pilomatrixoma 62
Pityriasis alba 340
Pityriasis lichenoides 142f
Pityriasis rosea 85, 128, 128f
secondary lesions of 129f
typical patch of 130f
Pityriasis versicolor 165, 166f, 167f, 337, 340, 444
demonstrates 337
Pityriasis, fine scale of 338f
Plaque 304
psoriasis 133f
dermoscopy of 132, 133f
Plasma cells 292f, 294f
Polylobular amorphous structure, white-yellowish 162f
Polymorphous interfollicular vessels 266f
enlarged 264
Polymorphous vascular structures 258f
Porokeratosis 374, 379f, 456
diagnosis of 456
histopathology confirmed diagnosis of 458f
Port-wine stain 380, 389, 389f, 391f, 392f, 401f
Postinflammatory process, part of 27
Prurigo nodularis 29, 29f, 64, 122f
Pruritic lesion 374f
Pseudocomedones 362f
Pseudohorn cysts 217f
Pseudonetwork 346
appearance of 61f
pattern 354f
Pseudopods 15, 65
Psoriasis 53, 132, 135f, 137f, 139f, 142f, 144f, 455, 456, 461
area severity index 5
dermoscopic hallmark of 50f
diagnosis of 132, 140f, 147
palmar 137f
palmoplantar 13, 137f, 138f
pustular 144f
treatment modified 452
Purpuric clothing dermatitis 441
Purpuric dermatoses, pigmented 85, 90f, 441
Pustulosis, palmoplantar 140f
Pyogenic granuloma 1, 380, 383, 384f388f, 463
seven dermoscopic patterns of 383t
shiny red nodule of 387f
R
Radial projection, gray-blue 64f
Radial streaming 15, 65f, 65, 448f
Rash
malar 295, 295f
mild erythematous 172f
photosensitive 295f
Red blood cell 263f, 406
Red globules and dots 490f
Red homogeneous area 384f, 387f, 388f
Red starburst pattern 34, 261f, 271f
Red vessels, arborizing 250f
Reticular
dermis, interstitium of 312f
pigment, normal 333
Reticuloglobular pattern 63f
Riehl's melanosis 353
Rosettes 235, 246f
S
Sarcoid
papular 82f
papule of 307f
Sarcoidosis 304, 434f
cutaneous 304
Scabetic nodule 180f
Scabies 178
dermoscopy of 178
Scales
over homogeneous brown background, reticular pattern of 200f
removal of 137f
Scalp 163f, 364f
psoriasis 22f, 141f
Scattered melanophages 83f
Sclerosis, dermal 408f
Sclerotic stroma 36f, 231f
Scurvy 441
Sebaceous gland 47f, 48f
hyperplastic 228f
multiple 48f
periphery of 47f
Sebaceous hyperplasia 24f, 85, 87f, 228, 229f, 435f
dermoscopy of 228
Seborrheic capitis, diagnosis of 176
Seborrheic dermatitis 53, 67f, 85, 88f
Seborrheic keratosis 51, 58f, 148, 203, 207, 208b, 209f, 210f, 212f221f, 411, 458, 460
combination of 216f
early 215f
exophytic papillary pattern of 221f
fat fingers 51f
lesion 58f
like dermatofibroma 194f, 195f, 201f
peripheral 197f, 201f
Senile comedones 443, 460
Short hairs, bending of 169f
Silvery white scales 133f, 136f
Single hair-bearing follicles 300f
SK See Seborrheic keratosis
Skin
asymptomatic hyperchromia of 351f
benign tumors of 182
colored flat topped lesions 235
diseases, granulomatous 302
lesions
asymptomatic 304f
dermoscopic diagnosis of 473
malignant tumors of 239
scrapings 174f
tumors 182
Small blood vessels 394
Small brown globules 184f
Soft tissue foreign bodies 429
Solar
elastosis 85, 86f
lentigines, fingerprint-like structures of 52f
lentigo 214f, 218f
Solitary dermatofibroma over forearm 192f
Solitary enlarging erythematous infiltrated plaque 314f
Spider angioma 76f
Spitz nevus 43
Squamous cell carcinoma 25, 62, 203, 250f, 257f
invasive 53, 257
Stasis pigmentation 441
Stratum
corneum 71f
spinosum 48
Streptococcal infection 142f
Subpapillary plexus 389, 390f
Sugar granules 428f
Superficial lymphatic malformation 394
Suprabasal acantholysis 368f
Sweat duct tumors 230
Syringoma 35f, 230, 230f232f
dermoscopy of 35f
over chin demonstrates 233f
Systemic lupus erythematosus 260, 295, 295f, 296f, 299f, 470f, 471f
Systemic retinoids 387f
T
Tadpole shaped ducts 36f, 232f
Tattoo 85, 430f
cutaneous reactions to 430
yellow 85
Tears, yellow 302
Telangiectasia 34f, 270f, 445
combination of 34f
eruptiva macularis perstans 445
fine-focused 313, 315f, 316f, 317f
Telangiectatic vessels 193f, 250f, 267
arborizing 416f
Terra firma-forme dermatosis 444
Thick white scales 273f
Tinea capitis 168, 168f, 170f, 171f
Tinea corporis 171
Tinea manuum 171
Tongue
dermoscopy of 93f
dorsum of 123f
Topical steroid 107f, 172f
Transient acantholytic dermatosis 366
Transverse white bands hairs 168
Trichoepithelioma 235, 238f
Trichophyton schoenleinii 168
Trichoscopy, polarized 170
Tuberous sclerosus 342
Tumors
adnexal 416, 435, 463
common cutaneous 185
U
Ulceration, central 302
Ulcers, mouth 260
Ultraviolet dermoscopy 170
V
Vascular dermoscopic patterns 21
Verruca plana 156
dermoscopic sign of 156
fleshy skin-colored macules of 156f
Verruca vulgaris 148, 149f, 412, 463
Vessels
arborizing 21, 25, 37, 37f, 38f, 227, 235, 248
arrangement of 21t
comma 21, 23
coral 21, 27
corkscrew 21, 26
crown 21, 24
description of 21t
dotted 21
glomerular 21, 26
grape-like 208
hairpin 21, 23
linear irregular 21, 26
pattern of 21, 21t
polymorphous 21, 28, 383
spermatozoa-like 254
Violaceous homogeneous pigmentation 196f
Vitiligo 333, 427f
dermoscopy of 334f
patch 335f
W
Warts 463
anogenital 93f
common 148
conglomeration of 158f
filiform 54f, 152, 152f
genital 153, 153f, 155
mosaic 158f
papillomatous 153
periungual 151f
plane 156
plantar 157, 157f
Warty papules 361f
over lower limb 378f
Weeping lesions over body folds 367f
White collarette 384f, 385f, 387f
White fibrotic beam 287
White patch
central star-like 193f
over neck 451f
White rail line 384f, 387f
White reticular streaks 317f
White roses pattern, bouquet of 31, 113f
White scales 261f
White shiny structures 79, 80f, 261f, 269, 273f, 275f, 280f, 285f, 287, 314f
White starburst pattern 29f, 275f, 302
White streaks and globules 199f
White structureless area 257, 258f, 280f, 282f, 283f, 285f
White track appearance 457f
Whitish veil 399
Wickham's striae 97, 102f, 105f, 110f, 122f, 455, 466f
demonstration of 3
determines 450
globular 108f
morphological patterns of 97b
patchy reticular pattern of 103f
patterns of 97, 466f
combined 97
globular 97
invisible 97
linear 97
perpendicular 97
radial streaming 97
reticular 97
veil like 97
remnant of 467f
reticular 68f
veil-like 103f, 109f, 122f
Wobble sign, dermoscopic demonstration of 69f
Y
Yellow clod sign 95
Yellow polylobular amorphous structure 161
Z
Zosteriform hyperpigmentation 421
Zosteriform lichen planus 119f, 120f
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Chapter Notes

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Dermoscopy: A Window into Epidermis and DermisCHAPTER 1

Purva Mehta,
Subrata Malakar
 
INTRODUCTION
Dermoscopy or epiluminescence microscopy is a simple, noninvasive method to examine the subsurface features of the skin invisible to the naked eye. It serves as a telescope through which the intricate details of a lesion in the epidermis and superficial dermis can be appreciated at a greater magnitude. Normally, light is reflected and scattered by the stratum corneum thus making the structures in the epidermis and superficial dermis invisible to the eye. This pitfall is superseded by a dermoscope, which decreases scattering of light and increases transillumination either through polarized light or through linkage fluids; allowing visualization of subsurface structures.
The orange hue at dawn signals the advent of the rising sun. Similarly, colors on dermoscopy underline the depth and nature of the structure being observed.
The naked eye cannot appreciate the vascular morphology of lesions such as a hemangioma or pyogenic granuloma. It is through the dermoscope that we can identify various vascular structures such as lacunae or red homogeneous areas and understand what the color red stands for. In dermoscopic language, it indicates either vasculature or traumatic extravasation of blood. Dermoscope provides a telescopic view into the vascular world of subsurface. It enlightens us not only about the location of the blood vessels but also their course in the dermis. Vessels seen as dots or loops on dermoscopy are placed in the papillary dermis whereas linear vessels correspond to the subpapillary plexus. Also, linearity of the vessels on dermoscopy suggests that they run parallel to the epidermis whereas dotted vessels signify a perpendicular orientation to the epidermis.
A granulomatous lesion like lupus vulgaris or sarcoidosis or a xanthogranuloma presents clinically in varied forms. Dermoscopy in such cases noninvasively demonstrates orangish yellow structures, which indicate granulomas, and guides the clinician towards correct differentials.
A nevus to the naked eye looks like an innocent macule or nodule. Dermoscopy provides a window into its subsurface and designates the location of melanocytes and the need for biopsy. A pigmented or a globular network suggests junctional activity of the melanocytes whereas a cobblestone pattern indicates a dermal nest of melanocytes. A clinical view of a pigmented lesion in most cases is inadequate to classify it as benign or malignant. Magnification on dermoscopy provides vital clues; eccrine atypical network or irregular streaks or a bizarre dermoscopic image leaning toward malignancy. Dermoscopy also helps to allocate the location of chromophores in the skin. Melanin in the upper and lower epidermis is seen through a dermoscope as black and brown respectively, whereas melanin in the papillary and reticular dermis is seen as gray and bluish gray respectively.
The naked eye is incapable of visualizing the shaft or the root of the hair. Dermoscopy offers a visual window into the appendageal world. If the hair root is destroyed, it will be seen as a fibrotic white dot on trichoscopy indicating cicatrization. A circumscribed bald patch on the scalp clinically ignites the possibilities of alopecia areata, trichotillomania, etc. But it is the demonstration of exclamation mark hair or Pohl-Pinkus constriction through a dermoscope that indicates disease activity in alopecia areata thereby offering a trichoscopic confirmation of the disease as well.
Dermoscopy opens up a whole new world of the subsurface. It is an essential tool in day-to-day practice as it offers a telescopic view of pigment patterns, vascular patters and appendageal structures.