![]() ![]() There are also studies showing a 50% incidence of a late asthmatic response in exercise-induced asthma, supporting the evidence for inflammation in EIA. Studies have shown other inflammatory markers to be present in patients with EIA at rest and also after exercise. Some studies have shown that exhaled nitric oxide (NO) changes after exercise in patients with EIA, and that this change is directly correlated with the drop in the forced expiratory volume in 1 second (FEV 1) after exercise. Inflammation of the Airways in Eiaīecause inflammation has been understood as the pathophysiologic basis for chronic asthma, evidence for inflammation has been studied in EIA and similar mediators have been found. This respiratory water loss increases the periciliary fluid lining the surface of respiratory mucosal membranes, leading to the influx of chloride and calcium ions into the bronchial epithelium, which further results in mediator release and, consequently, the pathophysiology of exercise-induced asthma. The reason for this water loss is the increasing ventilator rate, especially during inhalation of cold air. ![]() The other hypothesis suggests that water loss from the airways may be the reason for EIA. There is also considerable evidence to indicate that EIA is effected through the release of mediators from mast cells and other inflammatory cells of the airways. Furthermore, inhalation of cold air can induce vasoconstriction of the bronchial circulation, resulting in secondary reactive hyeraemia, further leading to oedema and airway narrowing. Airway cooling may stimulate receptors in the airways, causing bronchoconstriction through vagal stimulation. In one of the hypotheses, it has been suggested that airway cooling due to respiratory heat loss followed by hyperaemia and pulmonary vasodilatation could be the reason for asthma symptoms after exercising. Hence, it must be borne in mind that either term signifies the transient narrowing of the airways following exercise and that atopy causing chronic asthma and bronchial hyper-responsiveness to thermal, mechanical or osmotic stimuli (seen more commonly in elite athletes) are not mutually exclusive. Inhaled corticosteroids are a first-line therapy in terms of controller medications for athletes who have asthma and experience EIB.īecause of such close similarities between these terms, both are used interchangeably in much of the literature published across the world. Hence, the first-line treatment to minimize or prevent symptoms of EIB is the prophylactic use of short-acting bronchodilators shortly before exercise. The airway inflammation pattern is also different in these two conditions inflammation in asthma is usually associated with eosinophilia whereas isolated EIB in elite athletes seems to be more associated with neutrophilic or mixed-type airway inflammation and, hence, the efficacy of inhaled corticosteroids in this cohort is very unclear. ![]() In patients evaluated for EIB who have a normal physical examination and normal spirometry, bronchoprovocation testing is recommended. Most individuals who experience EIB will have normal baseline lung function, and spirometry alone is not adequate to diagnose EIB. Exercise can be the only stimulus that triggers respiratory symptoms in these patients. These patients who have EIB but not asthma do not exhibit the typical features of chronic asthma (i.e., frequent daytime symptoms, nocturnal symptoms, impaired lung function). EIB occurs in approximately 10% of individuals who are not known to have asthma. The term, EIA, is used to describe symptoms and signs of asthma provoked by exercisewhile EIB describes a reduction in lung function after an exercise test or a natural exercise and is usually seen in elite athletes who do not generally have asthma. However, there are some minor yet important differences in these two conditions. Exercise-induced asthma (EIA) and exercise-induced bronchospasm (EIB) are the terms that are usually used to describe the transient narrowing of the airways that follows vigorous exercise. ![]()
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