How are dermatomyositis and polymyositis treated?
Corticosteroids are considered first-line treatment usually starting with 1 mg/kg/day followed by a taper 4 weeks to several months after initiation.
If there is either no improvement with steroids or the steroids cannot be tapered, treatment with a second-line agent, usually intravenous immunoglobulin (IVIG), azathioprine, or methotrexate should be started.
Mycophenolate mofetil, tacrolimus, rituximab, cyclosporine, and cyclophosphamide can be used as well.
The choice often depends on extramuscular involvement as well as side effects.
