Hypersensitivity Pneumonitis

Hypersensitivity Pneumonitis
http://www.ajronline.org/cgi/content/full/174/4/1061

Luke D. Matar ; H. Page McAdams ; Thomas A. Sporn

Hypersensitivity pneumonitis, also known as extrinsic allergic alveolitis, is an inflammatory lung disease caused by inhalation of airborne organic particulate matter. These particles, which are usually 1-5 µm in diameter, deposit in distal air spaces and produce an immune-mediated inflammatory response in sensitized individuals. Causative agents are numerous and include bacteria, fungi, avian proteins, and wood dusts [1] (Table 1). Most exposures are occupational, but hobbies such as bird breeding are also implicated. The most common and well-studied forms of hypersensitivity pneumonitis are farmer’s lung and bird fancier’s lung [1].