A clinical, dermoscopic, and histopathological study of Dermatosis Papulosa Nigra (DPN) – An Indian perspective

Background Dermatosis papulosa nigra (DPN) is a benign cutaneous condition which commonly occurs in dark‐skinned people, especially Asians and African Americans. Owing to its benign nature and rarity, very few studies have been conducted to date, and dermoscopic studies are practically nonexistent. Objectives To study the clinical and epidemiological characteristics of patients with dermatosis papulosa nigra (DPN) and to correlate the clinical findings with dermoscopic and histopathological findings in DPN. Methods A total of 100 patients attending the Dermatology outpatient department at Father Muller Medical College, Mangalore, India, with clinically diagnosed dermatosis papulosa nigra were included in the study. Histopathology and dermoscopic evaluation of the lesions were done, and the characteristics seen were noted. Results Earlier onset of lesions was noted in our study, i.e. onset in the 4th decade as compared to the 6th decade in most other studies. A female preponderance, positive family history, history of sun exposure, and involvement of the head and neck were other significant associations. Histopathology revealed an acanthotic variant in all the lesions that were biopsied. The predominant dermoscopic finding was fissures and ridges of the cerebriform pattern followed by comedo‐like openings. Conclusion Dermatosis papulosa nigra is a benign unaesthetic condition seen in Fitzpatrick skin types IV‐VI. The diagnosis is mainly clinical; however, in a few cases histopathology and dermoscopy aid in differentiating it from other benign and malignant tumors. Dermoscopy, in particular, being a noninvasive investigative moiety is a rapid and accurate diagnostic tool.