Abstract

Exercise induced asthma (EIA) occurs in virtually all asthmatic persons. Prophylactic drugs are available but, in the recommended dosages, do not always provide total protection. Current evidence suggests that EIA is initiated by loss of water from the airways mucosa during exercise hyperpnea. The effects are probably mediated by an increase in the osmolarity of the fluid lining the respiratory epithelium. This may cause degranulation of pulmonary mast cells, stimulation of a vagal reflex, or both. The hypertensivity of asthmatics to respiratory water loss may derive from structural damage to the respiratory epithelium, perhaps compounded in some cases by abnormalities in adrenergic function. Various precautions can be taken by athmatic athletes to prevent or minimise EIA. Verf.-Referat