Extrinsic allergic alveolitis owing to hypersensitivity to chickens-significance of sputum precipitins.

This report describes 2 brothers 16 and 21 years of age, with clinical and pulmonary physiologic evidence of extrinsic allergic alveolitis that developed while working with chickens. Serum precipitins were demonstrated in both subjects against chicken serum, feathers, and droppings. Intradermal skin tests demonstrated both immediate and late skin reactions to chicken serum and feathers. Bronchial washing from the elder brother contained only weak precipitins against chicken serum, but strong precipitins against feathers. Results of inhalation challenge study in this subject confirmed that chicken feathers rather than chicken serum was the offending antigen. These data suggest that antibodies in the bronchial secretion may be pathogenetically more important than serum antibodies and that sputum precipitins may offer better diagnostic specificity than serum precipitins in this disease entity.