Hypersensitivity pneumonitis, also called extrinsic allergic alveolitis, is an inflammatory condition of the lung caused by the inhalation of small organic or, less commonly, inorganic particles in susceptible individuals. Some thirty different varieties of the condition have been described, the most common of which is known as "farmer's lung." Hypersensitivity pneumonitis represents an important category of occupational lung disease. The inhaled particles are usually fungal spores or bacteria that are found in moldy or rotting material, including hay, compost, bark, wood dust, and
JOHN L. STAUFFER
Murphy, D. M. F.; Morgan, W. K. C.; and Seaton, A. (1995). "Hypersensitivity Pneumonitis." In Occupational Lung Diseases, 3rd edition, eds. W. K. C. Morgan and A. Seaton. Philadelphia, PA: W. B. Saunders.