Dermoscopy

What is dermoscopy

Dermoscopy refers to the examination of the skin using skin surface microscopy, and is also called ‘dermatoscopy’, ‘epiluminoscopy’ and ‘epiluminescent microscopy’. Dermoscopy is mainly used to evaluate pigmented skin lesions. In experienced hands it can make it easier to diagnose melanoma.

Dermoscopy requires a high quality magnifying lens and a powerful lighting system. This allows examination of skin structures and patterns. There are several different lightweight, battery-powered hand-held devices. Convenient attachments allow video or still photography.

Dermoscopy

Skin examination using an Episcope

Photography using a DermLite Foto

Computer software can be used to archive the images and allow expert diagnosis and reporting (mole mapping). Smart programs aid in diagnosis by comparing the new image with stored cases with typical features of benign and malignant pigmented skin lesions.

Dermoscopic features of pigmented lesions

By dermoscopy, the pigmentation of the lesion is evaluated in terms of colour(s) and structure.

Colours found in pigmented skin lesions include black, brown, red, blue, grey, yellow and white.

The colours of dermoscopy

Ink-spot naevus

Benign mole

Blue naevus

Characteristics of the structure of the skin lesions include:

• Symmetry or asymmetry
• Homogeny/uniformity (sameness) or heterogeny (structural differences across the lesion)
• Distribution of pigment: network, pseudonetwork, blotches, dots, globules, cobblestoning, ovoid masses
• Skin surface keratin: milia, crypts, fissures
• Vascular pattern: regular or irregular
• Border of the lesion: fading or sharply cut off
• Presence of ulceration

There are specific dermoscopic patterns that aid in the diagnosis of the following pigmented skin lesions:

• Melanoma
• Moles (benign melanocytic naevus)
• Freckles (lentigos)
• Atypical naevi
• Blue naevi
• Seborrhoeic keratosis
• Pigmented basal cell carcinoma
• Haemangioma

Skin lesions viewed by dermoscopy

Early melanoma	Benign lentigo	Benign melanocytic naevus
Seborrhoeic keratosis	Basal cell carcinoma	Haemangioma

Dermoscopy may also be used for detailed skin surface examination in some other circumstances, for example:

• Finding a scabies mite within a burrow
• Locating a splinter
• Evaluating nail fold capillaries in cutaneous lupus erythematosus or systemic sclerosis