Nevus comedonicus with epidermolytic hyperkeratosis.
A 7-year-old girl had a linear nevus comedonicus affecting the right upper limb. Histologic examination of two biopsies specimens showed both the common changes of nevus comedonicus and the presence of epidermolytic hyperkeratosis. Therefore, nevus comedonicus should be included in the list of dermatoses having the distinctive histologic pattern of epidermolytic hyperkeratosis.