Ø  Dermoscopy is an indispensable tool to the clinical examination which is increasingly being used in general dermatology.

Ø  Dermoscopy allows the in vivo evaluation of colors and microstructures of the epidermis, the dermoepidermal junction, and the papillary dermis not visible to the naked eye.

Ø  An interface medium such as ultrasound gel or oil is applied to the skin to make the stratum corneum transparent, while the objective of the dermoscope is placed against the skin surface.

Ø  The instrument makes it possible to observe a vast new range of dermatological signs.

Quick facts in dermoscopy, trichoscopy and nail fold microscopy-

Scabies

1.      Triangle sign”, which represents the “head” portion of the mite.

2.      Delta wing jet with contrail” sign, corresponding to the head of the mite and the trailing burrow.

Sarcoidosis

1.      Yellow nodules (grains of sands), similar to diascopy sign.

2.      Yellow-brown discoloration (apple jelly sign), similar to diascopy sign.

Lichen planusà Wickham striae

Lymphangioma circumscriptumà Yellowish lacunes

Psoriatic lesions and psoriatic balanitisà “Bushy” capillaries at higher magnification and dotted vessels are seen throughout the entire lesion at lower magnification.

Angioma serpiginosum à Multiple, scattered, sharp lagoons

Dermatofibroma à

1.      Chrystalline structures

2.      Central white patch and peripheral pigment network

Clear cell acanthoma à Dotted vessels arranged in line like a string of pearls.

Seborrheic keratosis à

1.      Fingerprint pattern

2.      Fissures and ridges

3.      Milia like cysts

4.      Sharp demarcation

Acral nevi à Parallel furrow pattern

Hemangiomaà Well-demarcated dark red lacunae

Basal cell carcinoma

1.      Arborizing vessels

2.      Ulceration

Melanomaà

1.      Ugly duckling sign ,which means that nevi in the same individual tend to resemble one another, and that malignant melanoma often deviates from this nevus pattern

2.      Beauty and the beast sign

Androgenetic Alopecia

1.      Terminal to vellus hair ratio can be calculated without skin biopsies

2.      Predominance of hair follicle units with single hairs

3.      Hyperkeratotic plugs

4.      Variable hair shaft diameter

5.      Perifollicular pigmentation

Alopecia areata

1.      Yellow dots

2.      Cadaverized hairs

3.      Dystrophic hairs

4.      Micro-exclamation point hairs

Cicatricial Alopecia

1.      Fibrosis of follicular ostia visible as white dots

2.      Dots may coalesce to form bony white areas without visible ostia

Scleroderma

1.      Pearly shining areas, sclerosis “cotton balls”.

2.      Thin loops, megacapillaries.

3.      Rarefied capillaries (less than 6 loops per mm)

Systemic lupus erythematosus

1.      Considerable variation of loops, branching, twisted

2.      Microhemorrhage

Micro-Hutchinson’s sign à Pigmentation of the cuticle that can only be seen clearly with dermoscopy