Acute unilateral pneumonitis in a patient with polymyositis: a unique presentation of polymyositis-associated pneumonitis.

We describe a unique presentation of polymyositis-associated pneumonitis. A 45-year-old man with a history of polymyositis presented with an episode of fever, cough, dyspnea, rapidly progressive respiratory failure, and unilateral pulmonary infiltrates. Although bacterial pneumonia was initially suspected, all cultures, including bronchoalveolar cultures, remained negative, and the patient's condition worsened despite wide-spectrum antibiotics. Lung biopsy showed organizing pneumonia. The patient was treated with systemic corticosteroids and had complete resolution of respiratory failure and pulmonary infiltrates. We discuss polymyositis/dermatomyositis-associated pneumonitis.