Clinical features and diagnosis of aspirin induced asthma.

Although for therapeutic reasons it has become convenient to consider asthma as a single disease entity, this clearly is not the case, with many variants occurring. From a clinical standpoint, a minimal subdivision includes atopic asthma, cough variant asthma, brittle asthma, intrinsic asthma, occupational nonIgE dependent asthma, and aspirin intolerant asthma (AIA). This last variant constitutes a clearcut clinical syndrome. It is a remarkable model for investigating mechanisms that operate in asthma, rhinitis, and nasal polyposis. The recent introduction of anti-leukotriene drugs has amplified interest in this syndrome.