Nevus comedonicus associated with epidermal nevus.

A 21-year-old man had a zosteriform nevus comedonicus associated with a surrounding hyperpigmented maculopapular eruption, which had the histologic appearance of epidermal nevus. Scanning electron microscopic examinations of the comedones and the surrounding epidermal nevus showed a common feature, that is, chrysanthemum-like keratotic plugs. The association of a nevus comedonicus with an epidermal nevus and the common scanning electron microscopic findings of both suggest that a nevus comedonicus probably is an uncommon form of epidermal nevus.