Dermoscopic approach to hyperpigmented lesions in skin of color

Abstract

Hyperpigmented skin lesions are common presentation of Indian patients. It causes cosmetic disfigurement, as well as has immense psycho social impact. Most of the lesions are diagnosed clinically but some of them are difficult to diagnose because of overlapping features. To form basic dermoscopic guidelines to approach a hyperpigmented lesion. LPP and EDP demonstrate brownish background with bluish gray hue and brown to gray globules, which is also seen in PCD with superimposition of brown globules. Linear cristae cutis and sulci cutis forms a special clue in AN. Frictional melanosis displays bluish gray globules with patulous follicles with plugs and perifollicular scaling. Patulous follicular opening with whitish yellow excrescences on pseudopigment network is seen in seborrheic melanosis. PDL displays peri-follicular brown globules with no vasculature changes or scales. Melasma shows prominent brown background with reticular or reticulo-globular pigment pattern. Exogenous ochronosis demonstrates grayish brown globules with obliteration of follicular openings. Brown polygonal globules with scales along skin lines and over the globules are noted in CRP. Hub and spoke pattern of pigmentation is a feature of macular amyloidosis. Hyperpigmented pityriasis versicolor demonstrates accentuated pigment network with scaling in diffuse or perifollicular or along skin lines seen. Dermoscopic diagnosis should be based on amalgam of all parameters identified in a given lesion and not in isolation. Dermoscopy is of great importance for assessment of hyperpigmentation disorders in dark-skinned patients as they may clinically look similar due to the natural brownish background.