White Papules on the Backs of a Middle-Aged Man and His Son.

A middle-aged man came in for evaluation of "white spots" on his upper body. The number of lesions had increased progressively over the past 20 years but were asymptomatic. The patient expressed concern that his young son had recently developed similar lesions on the upper part of his back. Physical examination revealed numerous, slightly elevated, flat-topped papules scattered over the back, chest, and upper extremities (Figure 1). Each 4- to 6-mm papule was oval or round, ivory white, with a cobblestone surface. The patient's son was also examined and found to have six papules scattered across the upper part of his back and legs, identical in morphology to those of our patient. A shave biopsy was taken from of one of the papules. Results from routine hematoxylin-eosin, as well as Melan-A sections, are shown (Figure 2). The diagnosis was familial keratosis alba or familial hypochromic seborrheic keratosis.