Osteoma cutis as a presenting sign of pseudohypoparathyroidism.

Four unrelated children with osteoma cutis and Albright hereditary osteodystrophy (pseudohypoparathyroidism and pseudopseudohypoparathyroidism) are described. All four patients were normocalcemic when they were first seen with cutaneous ossification. A diagnosis of Albright hereditary osteodystrophy was established on the basis of associated somatic features, radiographic abnormalities, and family history. Progression to pseudohypoparathyroidism was documented in two children who developed hypocalcemia at 2 and 3 years of age, respectively. Early recognition of the skin manifestations of this syndrome and careful follow-up are important to prevent the deleterious effects of hypocalcemia. Osteoma cutis is a common sign of Albright hereditary osteodystrophy in infancy and childhood, and its significance should not be overlooked, even in the normocalcemic patient.