[Two cases of amyopathic dermatomyositis with fatal rapidly progressive interstitial pneumonitis]

Two middle-aged women showed typical erythematous heliotrope eruption and Gottron's sign without any symptom of myositis. The patients were diagnosed as 'amyopathic dermatomyositis' because of normal serum CPK levels, normal EMG and no histological abnormality by muscle biopsy. Clinical manifestations improved by the treatment with corticosteroids. During tapering of corticosteroids, however, intersititial pneumonitis developed and rapidly progressed. The first patients was treated with methylprednisolone pulse therapy, azathiopurine and methotrexate. The second patients was treated with betamethazone, methlprednisolone pulse therapy and cyclosporin A. In spite of these extensive immunosuppressive therapies, both patients died of pulmonary insufficiency a few months after admission. In the literature there has been only several cases of amyopathic dermatomyositis and only one case with fatal rapidly progressive interstitial pneumonitis. A new approach to the treatment of this disease should be made.