A 15-year-old African American girl was referred to our clinic for evaluation of untreated multiple papules and plaques on her hands and feet that had been present since birth. She occasionally bit the lesions. She had no history of excessive sun exposure or hyperhidrosis, but her father had similar lesions.
Physical examination revealed multiple crateriform hyperkeratotic papules located primarily at the boundary of the dorsal and plantar surfaces of the patient's hands (Figure 1) and feet. She also had hypopigmented, hyperkeratotic plaques overlying the distal interphalangeal and proximal interphalangeal and metacarpophalangeal joints of both hands (Figure 2), as well as the distal and proximal interphalangeal and metatarsophalangeal joints of both feet.