Unilateral Keratosis Follicularis

Abstract

Keratosis follicularis is a congenital skin disorder which begins usually in childhood and is characterized by keratotic follicular papules which later tend to become papillomatous. Sites of predilection are the head, face, extremities, chest, and inguinogenital regions. Generally, this is a symmetrical dermatosis, but unilateral involvement can occur.^1-4The following case report illustrates this rare atypical distribution which was so striking that the clinical impression of several dermatologists who examined the patient was verrucous epidermal nevus (nevus unius lateris). Report of Case An 18-year-old Caucasian youth presented himself to the dermatology clinic because of a pruritic papular eruption on the right side of the trunk and the right lower extremity. He stated that he had first noted clusters of small papules on the right hemithorax 14 months previously. Similar lesions appeared two and one-half weeks later on the right flank, the right thigh, and the right