A case of multiple nevoid hypertrichosis.

Nevoid hypertrichosis is an uncommon congenital disorder consisting of terminal hair growth in a localized distribution on flesh-colored skin; it is not associated with any other systemic abnormalities. A 21-year-old male patient had a circumscribed area of depigmented terminal hairs on his chest which had been present since 1 year of age. At the age of 18, similar lesions developed on his left shoulder and upper arm. The underlying skin was slightly hypopigmented, and no other systemic abnormalities were found. Histologic examination demonstrated terminal hair follicles in otherwise normal skin. The number of HMB 45 positive melanocytes was markedly decreased in the affected skin. This case of multiple nevoid hypertrichosis is reported with a review of previously reported cases.