Exercise-induced asthma

Exercise-induced bronchospasm depends on the level of ventilation and the weather conditions (temperature, humidity). It can thus occur often in high level athletes without a history of asthma. Bronchospasm occurring during or after exercise in an asthmatic patient is known as exercise-induced asthma. Its functional expression, a decrease in FEW., seems almost constant in asthmatic patients who are able to perform strenuous exercise, but its clinical expression is less frequent, in about one-third of these patients. Exercise-induced asthma is rarely an isolated phenomenon; when it is such, the diagnosis should be one of exclusion, especially in adults. Its pathophysiology depends on thermal and osmotic interactions in the inspired air in the lower airways, associated with an inflammatory response involving leukotrienes. Prevention of exercised-induced asthma is based on administration of montelukast or a short-acting beta-agonist, although the latter appears to be the less effective. These preventive treatments have demonstrated only a partial effect on the decrease of the FEV1 and the symptoms of the bronchospasm, their limited efficacy thus not completely preventing exercise-induced asthma. (C) 2013 Elsevier Masson SAS. All rights reserved.