EIA or Exercise-induced Bronchospasm?
The EIA Work Group of the American Academy of Allergy, Asthma and Immunology has defined EIA as 'the condition in which exercise induces symptoms of asthma in patients who have asthma'. Nonetheless, in many cases exercise is the primary – or only – apparent trigger of bronchospasm. While some investigators have labeled such cases as pure EIA,[3,4] a better term might be exercise-induced bronchospasm (EIB). EIB describes airway hyper-reactivity that is observed following exercise in a patient who does not otherwise present with daily and chronic asthma symptoms and who is not diagnosed with asthma according to current asthma management guidelines (Box 1).[1–3] In other words, these patients only have symptoms with exercise.
While patients with EIB do not have persistent asthma, they may have underlying airway inflammation similar to that which exists in asthma; indeed, frequent exercise has been demonstrated to be associated with proinflammatory changes; thus, symptoms observed only in relation to exercise or physical activity indicate the potential for increased expression of airway hyper-reactivity and the possible need for daily maintenance therapy. These patients should be monitored on a regular basis.
The different terminology may contribute to differences in the reported prevalences of EIA. For example, the prevalence of EIA in patients with asthma is estimated to be 90%, while estimates of EIA in the general healthy population range from 5 to 20%. Approximately 10% of otherwise healthy school children have been reported to have 'EIA without other daily symptoms of asthma'. The reported prevalence of EIA in elite athletes ranges from 16 to 70%.[1.3] Many elite athletes only have symptoms with exercise, and the broad variation in prevalence rates probably reflects the association with specific sports and how the estimates were determined (e.g., an empiric trial of medication vs challenge tests). Athletes undertaking winter endurance sports have some of the highest incidences of reported EIB.[1,3,6,7]
Expert Rev Clin Immunol. 2009;5(3) © 2009
Cite this: Challenges in the Management of Exercise-induced Asthma - Medscape - May 01, 2009.