Polymyositis with Lung Involvement Presenting as Bronchiolitis Obliterans Organizing Pneumonia-A Case Report

Abstract

The incidence of interstitial lung disease (ILD) in polymyositis (PM) is low, and the histological pattern of ILD as bronchiolitis obliterans with organizing pneumonia (BOOP) is even less. ILD in PM usually indicates a poor prognosis, unless the histological presentation is BOOP. We report a 61-year-old male without a history of cigarette smoking or systemic disease, who presented with fever, cough and dyspnea for 4 days before admission. Leukocytosis and elevated C-reactive protein were observed. Chest X-ray (CXR) revealed left lower lobe infiltrates. He was initially treated for pneumonia, but with a clinically poor response to antibiotics. Respiratory failure occurred and the CXR showed disease progression. Muscle weakness, tenderness, and elevated creatinine kinase developed after a few days. Upon completion of a series of studies, the diagnosis of PM with lung involvement presenting as BOOP was confirmed. Antibiotic was discontinued and steroid prescribed. The disease had a dramatic response to steroid therapy. The patient was then successfully weaned from the ventilator and later discharged.