Rapidly progressive interstitial lung disease associated with dermatomyositis responding to intravenous cyclophosphamide pulse therapy.

Interstitial lung disease, especially the rapidly progressive type, carries a grave prognosis when associated with polymyositis (PM)/dermatomyositis (DM). We describe a case of rapidly progressive interstitial lung disease associated with DM. Pathological findings included bronchiolitis obliterans organizing pneumonia (BOOP) pattern in the right upper lung lobe and interstitial fibrosis with microscopic honeycomb lesions in the right lower lung lobe. The patient's respiratory distress was severe and persistent, and oral intubation with mechanical ventilation was transitionally introduced. The respiratory distress condition responded to intravenous cyclophosphamide pulse therapy.