[Polymyositis-induced respiratory failure in the presence of antecedent pleural effusion].

Pulmonary involvement is generally recognized to be an important determinant of the clinical course in cases of polymyositis. A patient with bilateral pleural effusion as an initial symptom developed respiratory failure due to muscle weakness. Polymyositis was diagnosed on the basis of a muscle biopsy. A chemotherapy regimen consisting of methyl prednisolone (1 g/day for 3 days) followed by prednisolone (60 mg/day) alleviated, the pleural effusion and respiratory failure. Though pleural complications in polymyositis have been described mostly in association with concomitant interstitial lung disease, our patient exhibited only bilateral pleural effusion. Given that pleural effusion can be an initial symptom of polymyositis, it seems necessary that polymyositis be taken into consideration by differential diagnoses of pleural effusion of unknown etiology.