Coexistence of adult onset Still's disease and polymyositis with rhabdomyolysis successfully treated with methotrexate and corticosteroids.

Adult onset Still's disease is a disorder characterized by spiking fevers, rash, arthritis, serositis and myalgia. Erosive arthritis is a well recognized feature, however, myositis is not. We describe a patient with adult onset Still's disease, polymyositis (PM) and rhabdomyolysis successfully treated with methotrexate (MTX) and corticosteroids. This occurrence has previously been reported, however without the presence of rhabdomyolysis or treatment with MTX. Suppression of disease activity was followed by marked radiographic improvement of the arthritis. MTX and corticosteroids in combination may be indicated for the treatment of adult onset Still's disease when PM and erosive arthritis occur.