Clinical and Dermoscopic Features of Pigmented Disseminated Superficial Actinic Porokeratosis: Case Report and Literature Review

Abstract

Porokeratosis is a benign hyperkeratotic skin tumour due to a clonal proliferation of keratinocytes and is characterised by a telltale annular threadlike configuration along the border of a skin-colored to erythematous papule that can expand centrifugally. We are presenting a clinical and dermoscopic case of pigmented disseminated superficial actinic porokeratosis (DSAP) limited to the upper trunk of a white man with sun-damaged skin. A thorough review of PubMed failed to identify any previous reports on the dermoscopic appearance of pigmented porokeratosis. On dermoscopy, the presence of black dots limited to the periphery of the lesions is due to pigment incontinence and melanophages within the superficial papillary dermis limited to the area below the cornoid lamella. Pigmented DSAP is a unique morphological presentation of porokeratosis, and it is essential to be familiar with its clinical and dermoscopic presentation.