Bird Fancier's Lung

Abstract

Bird fancier's lung is an immunological lung disease induced by inhalation of bird droppings. The major responsible antigen is believed to IgA and metabolites of IgA. The clinical presentation of bird fancier's lung has been categorized into three clinical types, acute, recurrent relapsing eventually leading to chronic and initially chronic type. The disease process seems to be a combined reaction of immune complex and cellular immunity in acute and recurrent relapsing type. Acute symptoms are produced by IgA and/or IgG immune complexes and cellular immunity is important for persistence of the disease. Chronic type begins initially with chronic symptoms including cough & extertional dyspnea. Antibodies against crude bird-related antigens are not found in neither sera nor BAL fluids although IgG1 IgG3 and IgA1 subclass antibodies toward partially purified antigen are weakly positive. Although the long-term outcome of continued exposure to bird-related antigen is variable, avoidance of exposure is recommended.