Aspirin-induced asthma: new insights into pathogenesis and clinical presentation of drug intolerance.

Aspirin-induced asthma (AIA) is a distinct clinical syndrome, present in about 10% of adult asthmatics. Precipitation of the asthmatic attacks by aspirin and other nonsteroidal anti-inflammatory drugs is the hallmark of the syndrome. The idea that the attacks might result from the specific inhibition of a single enzyme in the respiratory tract, namely cyclooxygenase, has found support in experimental and clinical studies, and has generated a number of new hypotheses on the mechanism of bronchoconstriction. These hypotheses, operating within the frame of cyclooxygenase theory, point to the involvement of leukotrienes, platelets or chronic viral infection. Progress in studies on AIA has improved our knowledge on the drugs - safe and contraindicated - in this relatively common and fascinating clinical syndrome. Studies on mechanisms operating in AIA might eventually lead to new insights in pathogenesis of bronchial asthma.