Inflammatory myopathies: how to treat the difficult cases.

The initial approach to the treatment of patients with inflammatory myopathy is critical in determining the subsequent course and outcome. Prolonged administration of high doses of corticosteroids should be avoided and a second-line agent such as methotrexate or azathioprine should be introduced earlier rather than later. Intravenous immunoglobulin therapy has an important place if the myositis remains active, particularly in patients with dermatomyositis, and is the treatment of choice in patients with immunodeficiency who are not controlled by corticosteroids. In more resistant cases of polymyositis or dermatomyositis it may be necessary to use cyclophosphamide, cyclosporin or the promising newer immunosuppressive agents mycophenolate mofetil or tacrolimus to achieve disease control. The treatment of inclusion body myositis remains unsatisfactory but a trial of prednisolone and methotrexate is warranted in selected patients.