[Prognosis of interstitial pneumonitis (IP) in polymyositis (PM)/dermatomyositis (DM)].

IP, the major complication of PM/DM, is closely related to the life of these patients. In this study the course and prognosis of IP associated with PM/DM were investigated. Thirty IP patients with PM/DM were divided into 4 groups according to the course of IP. Clinical manifestations, laboratory data, chest radiographs and treatment were examined retrospectively. Eleven cases improved (Group I), 11 cases were exacerbated (Group E), 3 cases were unchanged (Group U), 2 cases died due to rapid progression of IP (Group D) and 3 cases dropped out. Both Group D patients were middle aged female DM patients without CPK elevation. All cases were treated with corticosteroids. The clinical manifestations, laboratory data, chest radiographs and initial dose of corticosteroid were not markedly different between Group I and E. The total dose of corticosteroids during the first 3 months tended to be higher in Group I than in Group E. Unlike idiopathic interstitial pneumonitis, the decrease in lung volume on chest radiographs improved after the treatment in 5 cases. We conclude that IP associated with PM/DM should be treated initially with high doses of corticosteroids.