Topographic dermoscopy is an advanced approach in dermatology that adapts dermoscopic examination techniques to specific anatomical locations, recognizing that skin morphology, appendage distribution, and environmental exposure significantly influence dermoscopic patterns. This method enhances diagnostic precision by integrating regional context into the interpretation of dermoscopic features.

On the face, dermoscopy reveals distinct characteristics due to the high density of pilosebaceous units, thin epidermis, and chronic sun exposure. Common findings include a pseudonetwork caused by interruption of pigmentation around follicles, annular-granular structures, and yellowish globules. Facial lentigines, actinic keratoses, and early lentigo maligna each present region-specific clues that differ from their counterparts on the trunk or limbs.

The auricular region (ear) poses particular challenges due to its concave and convex contours and sebaceous-rich but hairless skin. Dermoscopy in this area helps differentiate between benign lesions such as seborrheic keratoses and high-risk entities like lentigo maligna or basal cell carcinoma, which often show linear irregular vessels, shiny white structures, or asymmetric pigmented networks.

On the chest and back, where the skin is thicker and often exposed to intermittent sun exposure, dermoscopic patterns may include structureless pigmentation, regression structures, or atypical pigment networks. Special attention is needed for large congenital or acquired nevi, as well as for early melanoma that may not yet present classical dermoscopic criteria.

Lesions on the limbs are influenced by friction, mechanical trauma, and variable vascularization. Dermoscopy in these regions often shows polymorphous vessels, globules, or clods with pigmentation patterns that may mimic malignancy, especially in areas of chronic irritation.

The palms and soles (acral regions) require specific dermoscopic criteria due to their unique ridge and furrow anatomy. The parallel ridge pattern is a hallmark of melanoma, while the parallel furrow, lattice-like, and fibrillar patterns are more common in benign melanocytic nevi. Understanding the alignment of pigmentation with skin furrows or ridges is key to accurate diagnosis.

Scalp and hair disorders are assessed using trichoscopy, a specialized form of dermoscopy that identifies follicular openings, peripilar signs, hair shaft anomalies, and perifollicular changes. Common trichoscopic features include yellow dots in alopecia areata, miniaturized hairs in androgenetic alopecia, and comma hairs or corkscrew hairs in tinea capitis.

Nail disorders benefit from onychoscopic evaluation, especially when assessing longitudinal melanonychia, hemorrhages, nail matrix pigmentation, or dystrophic changes. Dermoscopy distinguishes between benign pigmentation (e.g., ethnic melanonychia or nail matrix nevi) and alarming features such as Hutchinson’s sign or irregular pigment bands indicative of subungual melanoma.

Mucosal dermoscopy provides additional diagnostic support for pigmented and vascular lesions of the lips, oral cavity, and genitalia. Although challenging due to moisture and mobility, mucoscopy can reveal blue-white veils, multiple colors, or irregular vessels in suspicious mucosal melanomas or vascular tumors.

An emerging adjunct to topographic dermoscopy is ultraviolet dermoscopy. Under UV light, certain organisms and structures fluoresce, aiding in diagnosis. For instance, scabies mites appear as bright green dots under UV dermoscopy, allowing rapid confirmation of infestation even in atypical presentations.

Overall, topographic dermoscopy enhances dermatological diagnostics by tailoring interpretation to regional anatomy, improving sensitivity and specificity, and guiding targeted management strategies.