Epidermolytic hyperkeratosis and congenital platelike osteoma cutis in a child.

Epidermolytic hyperkeratosis is a rare congenital ichthyosis. Platelike osteoma cutis also is a rare diagnosis and is associated with abnormal ossification of cutaneous or subcutaneous tissue. A 17-month-old Hispanic girl presented with a plate of subcutaneous bone since birth as well as considerable scaling and hyperkeratosis centered around the joints. Histologic examination confirmed the diagnosis of both epidermolytic hyperkeratosis and osteoma cutis. Although there have been some cases of epidermolytic hyperkeratosis with other dermatologic conditions, we report a rare case of epidermolytic hyperkeratosis and platelike osteoma cutis.