[A case of summer type hypersensitivity pneumonitis resulting in chronic respiratory failure and cor pulmonale].

A female case of Japanese summer-type hypersensitivity pneumonitis who was a smoker developed in chronic respiratory failure several years later. Biopsy specimen on first admission showed findings of granulomatous bronchioloalveolitis distributed in the center of secondary lobules. Pulmonary function studies demonstrated restrictive disease with high RV% and low airway conductance. In spite of steroid therapy, dyspnea persisted and the same symptoms were found on next summer. Six years later symptoms of chronic respiratory failure and cor pulmonale developed. Chest X-Ray showed dilated pulmonary artery, cardiomegaly and overinflation without apparent fibrosis. Hypoxemia and hypercapnia were also seen on blood gas analysis. Pulmonary function was unchanged compared to the findings on first admission. Since then long term oxygen therapy was started. It was thought that irreversible small airway disease caused by hypersensitivity pneumonitis was attributable to cor pulmonale and chronic respiratory failure because of her smoking habit and long period of exposure to antigen. As a patient with summer type hypersensitivity pneumonitis always has a possibility of chronic disease developing after long term exposure to antigen, such as a farmer's lung, the cessation of exposure to antigen by complete cleaning up of the patient's environment or moving out were considered to be important.