Polymyositis/dermatomyositis: clinical features and outcome in 22 patients.

Twenty-two adult patients with polymyositis/dermatomyositis (PM/DM) have been seen at the Sir Mortimer B. Davis-Jewish General Hospital since 1970. DM accounted for 50% of the patients. Malignancy was found within 3 years of presentation in 32% and was present in 46% of patients over age 50. Forty-six percent of patients with DM versus 18% of those with PM had a malignancy. Seven patients died. Fourteen patients were seen at a mean followup of 5.6 years. By life-table analysis, 42% of patients terminated corticosteroids within 3 years from diagnosis. The mean dose of prednisone in 8 patients being treated at followup was 11.7 mg daily. Functional disability, however, was common at followup. Thirty-six percent had substantial disability related to the disease or its treatment.