Challenge of exercise-induced asthma and exercise-induced bronchoconstriction.

Exertional dyspnea is a common clinical problem seen with different etiologies in different clinical situations and may even be found in healthy individuals. Approximately 90% of asthmatic patients suffer from shortness of breath in the context of exercise. Dyspnea, occurring during or after exercise, can be the only clinical manifestation of asthma. On the other hand, bronchoconstriction may occur in the absence of asthma - so-called exercise-induced bronchoconstriction. In elite athletes and persons performing sports with high ventilatory demand, bronchospasm in the context of exercise may appear without the presence of asthma. In these circumstances, bronchoconstriction is characterized by neutrophilic inflammation in the bronchial epithelium. Exercise-induced bronchoconstriction in the absence of asthma is difficult to diagnose and to treat. Diagnostic tests are often complex to handle, infrequently performed and the majority miss well-defined cut-off points. Diagnosis is confirmed either by performing direct or indirect bronchial challenge tests for classical asthma or through indirect tests for exercise-induced bronchoconstriction. Therapy for both diseases is based on short-acting beta-agonists used 15 min before exercise. Daily basic therapy is different for asthmatics and nonasthmatics - where basic therapy consists of inhaled corticosteroids in asthmatics, leukotriene antagonists play a more important role in exercise-induced bronchoconstriction. In general, treatment of exercise-induced asthma follows the Global Initiative of Asthma guidelines.