Pulmonary function studies in bird breeder's lung.

Pulmonary function studies were performed at the time of diagnosis in 10 patients, aged between 11 and 51 years, with bird breeder's lung due to exposure of between 9 months and 42 years. The studies were repeated after a varying interval in nine of these patients, following removal from exposure. In initial tests, diffusing capacity was impaired in eight patients and the arterial oxygen tension at rest was below 80 mm. Hg in seven. Five patients had a low vital capacity and three showed evidence of airway obstruction. One patient continued to breed pigeons, against medical advice, and his pulmonary function, repeated after nine months, showed further deterioration. The others with abnormal pulmonary function showed significant improvement on repeat studies. Pulmonary function studies appear to be helpful in the diagnosis, irrespective of radio-graphic changes, and in the follow-up of patients. Since the description of three patients with acute pneumonitis following exposure to pigeons which they bred as a hobby (Reed, Sosman, and Barbee, 1965), there have been a number of reports of interstitial pulmonary diseases in non-atopic subjects which appear to have been due to hyper-sensitive reactions to the excreta of both pigeons and budgerigars, similar to those due to other inhaled organic dusts. The clinical features are characterized by an acute or insidious onset of dyspnoea, tachypnoea, fever, cough, malaise, loss of weight, and crepita-tions at the lung bases. Radiographs may appear normal or show micronodular shadowing in the early stages, but continued exposure often leads to further mottling, diffuse reticulation, and fibrosis (Leading article, 1967). In the serum of affected patients, specific precipitins have been demonstrated to antigens derived from both pigeon and budgerigar material though the presence of serum precipitins in bird breeders without any pulmonary symptom is not uncommon (Hargreave et al., 1966; Maloney, 1967). In most patients, intracutaneous tests with extracts of serum or droppings give a late Arthus-type response with an occasional immediate reaction. Aerosol challenge with appropriate antigen has been used as a diagnostic aid in adults, but such provocative tests do not seem to be an essential procedure (Stiehm et al., 1967). The purpose of the present study is to present data of some of the main lung function changes in bird breeder's lung and to demonstrate the effect of removal from the source of exposure on these changes. MATERIALS AND METHODS Ten patients with bird breeder's lung were studied. Details of …