Localized Dowling-Degos disease

Abstract

A 26-year-old young man came with complaints of abnormally dark skin coloring, particularly in the back of the hands and intertriginous folds between digits, progressively spreading in the last 5 years. There was no family history of the same. He had no personal and family history of skin disease or diabetes mellitus. A clinical diagnosis of drug-induced hyperpigmentation disorder was made. A skin biopsy of 0.3 cm × 0.3 cm which was totally embedded for histopathology reporting was obtained. The section revealed epidermis, dermis, and subcutaneous tissue. Epidermis shows hyperkeratosis, irregular acanthosis with focal filliform down growth of the epidermis. Multiple keratin horn cysts were seen in the down growth. The tips of rete ridges showed pronounced hyperpigmentation. The histopathological impression was Dowling-Degos disease (DDD). DDD is a rare genetic skin condition without a definite cure, although its prevalence is unknown. We report a DDD case in a young man.