Bypass phrynoderma. Vitamin A deficiency associated with bowel-bypass surgery.

A 41-year-old woman had multiple keratotic papules and nodules on the trunk and extremities four years after a bowel-bypass procedure for morbid obesity. The microscopic features were those of a perforating folliculitis. Serum vitamin A levels were extremely low. Oral vitamin A therapy resulted in dramatic improvement of the cutaneous lesions.