History
Patients with exercise-induced asthma (EIA) usually present complaining of exercise-related respiratory symptoms. This complaint is much more common among children and younger athletes but can be seen at any age.
Symptoms during or following exercise include the following [1, 3, 16] :
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Chest tightness or pain
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Cough
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Shortness of breath
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Wheezing
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Underperformance or poor performance on the field of play
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Fatigue
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Prolonged recovery time
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Gastrointestinal (GI) discomfort
The following factors may cause patients to deny symptoms:
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Peer pressure
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Embarrassment
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Fear of losing position on the team
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Misinterpretation as postexercise fatigue
Factors contributing to EIA consist of the following:
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Cool temperatures
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Low-humidity environment
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Poor air quality
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High pollen counts
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Coincident respiratory infection
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Poor physical conditioning
Exercise factors can include the following:
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Aerobic exercise appears to be much more problematic than anaerobic exercise.
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Duration of aerobic activity greater than 8-10 minutes provokes EIA.
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High-intensity aerobic exercise also provokes EIA.
Weiler et al conducted a systematic review of the literature that evaluated the accuracy of exercise-induced bronchoconstriction (EIB) screening questionnaires that might be adopted for widespread EIB screening in the general population. Results of this review indicated that no existing EIB screening questionnaire had adequate sensitivity and specificity for this purpose. [17]
Physical Examination
The patient's physical examination is often unremarkable in the clinical setting; a higher yield is obtained on the field or after an exercise challenge. [5] Exercise challenge, for the purpose of the physical examination, may be informal. For example, the clinician may have the athlete come to the office wearing athletic clothing and run on a treadmill or around the parking lot for 10 minutes, which is then followed by another pulmonary examination.
The physical examination should include the following areas:
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Skin - Note any signs of atopic disease.
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Head, ears, eyes, nose, and throat - Note any evidence of acute infection, chronic infection, and/or allergic/atopic disease.
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Pharynx - Note any mucus, cobblestoning, and/or erythema.
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Nose - Note the presence of enlarged turbinates, erythema, and/or congestion.
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Sinuses - Note the presence of tenderness.
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Lungs - Note the presence of rales, rhonchi, wheezes, and/or a prolonged expiratory phase.
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Heart - Note the presence of murmurs and/or an irregular rhythm.
Phases of EIA
There is a time interval between sessions of aerobic exercise. This interval includes the refractory and late-phases.
Refractory phase
The refractory phase starts less than 1 hour after the initial aerobic exercise and lasts up to 3 hours. This phase is unpredictable and intermittent and results in as little as one half the degree of bronchospasm as in the first episode. The warm-up period can be used in an attempt to ensure that competition occurs during this refractory phase.
The mechanism is unknown but is believed to involve the following possibilities: depletion of mast cell mediators, release of endogenous catecholamines, and release of endogenous protective prostaglandins.
Late-phase response
This phase occurs 3-9 hours after the initial exercise challenge, and unlike the refractory phase, the late phase manifests as an increase in symptoms, with cough, wheezing, or shortness of breath. This response is much more common in children, usually less severe than the early response, and more likely to occur if severe early exercise-induced bronchospasm (EIB) is present.
Complications
The common pitfalls in asthma occur with downplaying of symptoms or patient complaints. Complications of an untreated asthma attack include progression to status asthmaticus, respiratory failure, and even death. More commonly, an anxiety attack can be precipitated secondary to dyspnea.
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Pathogenesis of asthma. Antigen presentation by the dendritic cell with the lymphocyte and cytokine response leading to airway inflammation and asthma symptoms.
