A case of bird fancier's lung caused by contact with wild birds

Hypersensitivity pneumonitis (HP) is an immunologically mediated lung disease due to the repetitive inhalation of antigens. Bird fancier's lung (BFL) is one of the common types of HP caused by the bird-related antigens. A 72-years-old male was admitted to our hospital with symptoms of cough and dyspnea on exertion. He had been breeding wild birds for 20 years. We found a decrease of Pa02 and diffuse bilateral ground-glass opacities on his chest XP and CT. After admission the patient's symptoms improved without therapy. Increase of lymphocytes and neutrophils in bronchoalveolar lavage fluid (BALF) and alveolitis in a transbronchial lung biopsy (TBLB) were detected. Also the patient's serum showed positive reaction to precipitation against droppings of his birds. As a result of these findings, we diagnosed this case as an acute BFL provoked by close contact with wild birds. Avoidance of antigens and steroid treatment led him to rapid improvement. Because BFL is a potentially severe disease that can progress to respiratory failure, early diagnosis and avoidance from antigens are needed. So careful questions for emviromental features and birds breeding history are very important.