Childhood scleromyositis: an overlap syndrome associated with PM-Scl antibody.

Fourteen patients with childhood scleromyositis followed from 1 to more than 10 years experienced concomitant sclerodermoid and dermatomyositis features, variably expressed at one time or another during the course of the disease. The most characteristic features were myalgia-myositis, arthralgia-arthritis, puffy, atrophic, sclerotic fingers, and Raynaud's phenomenon. This overlap syndrome was the most frequent sclerodermoid condition in children, differing from both systemic scleroderma and dermatomyositis. The course of the disease was protracted and rather benign, and PM-Scl antibody was an important diagnostic and prognostic marker. We present criteria for diagnosis of scleromyositis and its differentiation from systemic scleroderma, dermatomyositis, and Sharp overlap syndrome.