Exercise-induced asthma. Diagnostic clues with recommendation for treatment.

Exercise-induced bronchospasm, a very common component of asthma, may be quite bothersome and interfere with activities. The etiology appears to be related to the degree of heat loss in the tracheobronchial tree and to release of mediators from the mast cells. Exercise-induced asthma can be effectively treated, preferably with preventive medications such as beta 2 agonists or cromolyn (Intal). In the future, drugs such as nifedipine (Procardia) may also be useful, but as yet no calcium channel blocker has been approved for this indication.