[A case of hypersensitivity pneumonitis caused by zinc fume].

A 55-year-old man with a 3-year occupational history of welding was admitted for repeated episodes of fever, cough and dyspnea after inhalation of smoke while welding galvanized steel. A computed tomography (CT) showed diffuse centrilobular nodules, panlobular ground-glass opacity and interlobular septal thickening in both lung fields, and he suffered from hypoxemia (PaO2 = 55.3Torr) while breathing room air. Percentage of lymphocytes in bronchoalveolar lavage fluid increased, and lung biopsy specimens at thoracoscopy revealed lymphocytic alveolitis and organization in air spaces. His symptoms and signs disappeared spontaneously only when he ceased welding. Panlobular ground-glass opacity and interlobular septal thickening improved immediately with oral corticosteroids. Patch tests using metal series gave positive reactions to zinc. We diagnosed this case as hypersensitivity pneumonitis caused by zinc fumes.