Treatment of idiopathic inflammatory myopathies

This article reviews the results of recent therapeutic trials in dermatomyositis, polymyositis, and inclusion body myositis and suggests an approach to treating patients with inflammatory myopathy.

We reviewed 10 double-blind, placebo-controlled therapeutic trials in patients with inflammatory myopathy. Only one, using intravenous immunoglobulin in refractory dermatomyositis, indicated benefit. A brief trial of azathioprine in polymyositis and eight studies using various treatments in inclusion body myositis did not show benefit.

There have been no adequate double-blind, placebo-controlled therapeutic trials of dermatomyositis and polymyositis. It is generally accepted, however, that these disorders respond to immunosuppressive agents. Prednisone is usually the initial treatment. There is no agreement on how prednisone should be administered and even less agreement about other agents. Inclusion body myositis, which now appears to be the most common (in adults), is unresponsive to immunosuppressive and immunomodulating therapies. There are candidate treatments for inclusion body myositis and a need for additional double-blind, placebo-controlled therapeutic trials in all patients with inflammatory myopathy.