OCCUPATIONAL EXTRINSIC ALLERGIC ALVEOLITI S

Occupational factors encountered in farming and other agricultural act ivities produce a particular risk for respiratory diseases. For some, such as extrinsic allergic alveolitis, diagnosis depends upon a range of epidemiological, clinical, radiological and immunological arguments . Farmer's lung is one of the most common form of extrinsic allergic a lveolitis. Bird breeder's lung is another, the List is long. The envir onmental allergens likely to affect alveoli and interstitial tissues h ave been identified, but simple detection of antibodies does not const itute a pathognomonic criterion of extrinsic allergic alveolitis. Co-i mmuno-electrodiffusion is a rapid and sensitive technique for the demo nstration of remarkable precipitating systems of extrinsic allergic al veolitis. This investigation enables subjects who really have the dise ase to be distinguished from contact subjects. Diagnosis is important to prevent development of a disabling and irreversible pulmonary fibro sis.