Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease caused by inhalation of various environmental and occupational antigens. Occupational exposure to polyurethane is an under-recognized cause, particularly in developing countries. We report a 40-year-old non-smoker employed as a supervisor in a footwear manufacturing factory who presented with recurrent episodes of acute hypoxemic respiratory failure over a period of 3 years. He had multiple hospitalizations and was repeatedly treated for presumed infective and obstructive airway disease, including a trial of antitubercular therapy based on a positive bronchoalveolar lavage (BAL) nucleic acid amplification test, without clinical improvement. On presentation to our center, detailed evaluation revealed lymphocyte-predominant BAL, fibrotic changes on transbronchial lung biopsy, and high-resolution computed tomography findings consistent with fibrotic HP. A comprehensive occupational history revealed significant exposure to polyurethane, supported by clinical findings of dental erosion and chemical stains on clothing. The patient showed marked clinical and radiological improvement following corticosteroid therapy and strict antigen avoidance. This case emphasizes the importance of meticulous occupational history in patients with recurrent or unexplained interstitial lung disease and highlights polyurethane-induced HP as a preventable cause of progressive fibrotic lung disease.
Gothi et al. (Wed,) studied this question.