Allergen-induced late asthmatic responses and increased airway responsiveness

Our understanding of the airway response to inhaled allergens has increased substantially over the past several years. In addition to the long-recognized immediate or early asthmatic response, allergens also cause late asthmatic responses and allergen-induced increase in airway responsiveness to nonsensitizing stimuli such as exercise, cold air, histamine, and methacholine. These late sequelae are most likely due to airway inflammation and appear to be more clinically relevant than is the early response in the pathogenesis of clinical atopic allergic asthma.