Exercise-Induced Asthma
Michael A. Krafczyk
Christopher Cieurzo
BasicsDescription
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Airway bronchoconstriction characterized by wheezing, coughing, shortness of breath, and/or chest tightness occurring during or after exercise
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If the athlete has underlying asthma, then it is called exercise-induced asthma; otherwise, it is exercise-induced bronchoconstriction.
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Usually within 5–15 min of the onset of exercise, an acute episode of airway obstruction begins. This is usually followed by recovery within 30–90 min on completion of the exercise.
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Synonym(s): Exercise-induced bronchoconstriction
Epidemiology
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10–50% of recreational and elite athletes
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70–80% of asthmatics
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40% of patients with allergic rhinitis
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35–50% of cold-weather athletes
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No gender or age differences have been noted.
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A high level of fitness does not confer immunity from either asthma or exercise-induced bronchocon-striction (EIB).
Risk Factors
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Cold-weather sports such as ice hockey, figure skating, and cross-country skiing
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Sports with a long duration of high-intensity exercise such as running, bicycling, swimming, soccer, and rugby
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Environmental factors such as tobacco smoke, chlorine, sulfur dioxide, nitrogen oxide, carbon monoxide, pollens and molds, cold weather, and low humidity
Etiology
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Hyperosmolarity theory posits that increased airflow, particularly of unhumidified air, causes water loss from the surface liquid of the airways. This causes a hyperosmolar state in the airways, leading to inflammation and bronchoconstriction.
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Airway rewarming theory suggests that increased respiratory rate cools the cells on the surface of the airways. Once exertion subsides, the airways rewarm, causing dilatation of the airway blood vessels, leading to hyperemia and fluid leakage into the bronchioles. This, in turn, causes inflammation and airway constriction.
Commonly Associated Conditions
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Asthma
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Allergic rhinitis and hay fever
Diagnosis-
Direct testing with pulmonary function tests (PFTs) done before and after albuterol should be done 1st (1)[A].
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If negative, then move on to indirect testing with one of the following.
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PFTs before and after exercise (1)[A]:
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Spirometry more accurate than peak expiratory flow rate
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10–15% reduction in preexercise forced expiratory capacity in 1 sec (FEV1) confirms the diagnosis of EIB.
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Best to test athletes during sport-specific exercise or at temperatures of 20–25°C and <50% relative humidity
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Exercise at a workload of 80–90% of predicted VO2,max for 6–8 min during testing
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Eucapnic voluntary hyperventilation (1)[A]:
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Recommended by IOC Medical Commission for diagnosing athletes
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Hyperventilation of a gas mixture with 21% O2 and 5% CO2 for 6 min at 85% maximum voluntary ventilation
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FEV1 is measured prior to the test and 5, 10, and 15 min after the test.
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90% sensitive when 10% drop in FEV1 is used as cutoff; 100% sensitive when a drop of 15% is used.
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Inhaled mannitol testing shows high sensitivity and specificity for exercise-induced asthma (EIA) and is likely to become another diagnostic tool (2,1)[A].
History
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Personal or family history of allergies or asthma
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Symptoms are often a poor predictor of who has EIA.
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Symptoms occur during or after exercise, typically appearing after 6–8 min of exercise.
Physical Exam
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Signs and symptoms include:
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Coughing
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Wheezing
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Shortness of breath
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Chest tightness
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Abdominal pain
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Headache
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Fatigue
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Feeling out of shape
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Chest pain or discomfort
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Physical examination should include the following:
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Look for evidence of allergic disease such as pale nasal mucosa or allergic “shiners.”
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Cardiac exam to evaluate for cardiac abnormalities
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Lung examination typically normal; if wheezing, consider chronic asthma.
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On the field or after exercise challenge, physical examination is more likely to reveal wheezing.
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Differential Diagnosis
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Pulmonary:
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Asthma with exercise exacerbation
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Exercise-induced hyperventilation
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Restrictive lung disease
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Cystic fibrosis
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Cardiac:
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Coronary artery disease
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Congenital/acquired heart defects
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Arrhythmias
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Congestive heart failure
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Cardiomyopathy
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ENT:
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Vocal cord dysfunction
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Laryngeal prolapse
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Exercise-induced laryngeal dysfunction
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Laryngomalacia
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Chronic sinusitis
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GI: Gastroesophageal reflux disease
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Allergic: Exercise-induced anaphylaxis/urticaria
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Other:
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General state of deconditioning
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Anxiety disorders, panic attacks
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Treatment-
Warm-up of 15 min at moderate exertion 15–30 min prior to exercise can induce a refractory period preventing bronchoconstriction.
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Avoidance of triggers
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In cold weather, a mask can be used to warm the air.
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Nose breathing can help to warm and moisturize the air.
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Athletes with underlying asthma should be well controlled before beginning a sport/exercise program.
P.143
Medication
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Short-acting beta agonists
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Oral steroids for severe exacerbation
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Treat as per asthma guidelines (National Heart, Blood, and Lung Institute), particularly for patients with underlying asthma.
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Inhaled corticosteroids do not typically help in the acute setting.
First Line
Prophylactic (preexercise) medication:
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Short-acting beta agonist: 2–4 puffs 15–30 min before exercise; may repeat during exercise as needed (3)[A]
Second Line
If not responding adequately to a short-acting beta agonist, can add:
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Cromolyn 4–10 puffs 10–20 min before exercise (3)[A]
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Nedocromil 2–4 puffs 10–20 min before exercise (3)[A]
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Montelukast 10 mg PO up to 2 hr before exercise (3)[A]; consider in athletes with allergic rhinitis.
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Long-acting beta agonist (LABA), such as formoterol and salmeterol, in conjunction with inhaled corticosteroids 30–60 min before exercise (3)[A]
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Avoid use of LABA without inhaled corticosteroids based on a recent study showing increased incidence of asthma-related events when LABAs are used alone (4).
Additional Treatment
Additional Therapies
For elite athletes, check the U.S. Olympic Committee or National Collegiate Athletic Association list of banned substances to be sure that the medications used are in compliance with their rules.
Complementary and Alternative Medicine
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High-dose omega-3 fish oil
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Pycnogenol 30–100 mg/day or 10 mg/kg/day taken 2–3 times a day
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Breathing exercises/relaxation techniques may be tried.
Ongoing Care-
Daily medication:
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Cromolyn: 2 puffs q.i.d. or 4 puffs b.i.d. (3)[A]
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Nedocromil: 2 puffs q.i.d. (3)[A]
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Montelukast 10 mg daily (3)[B]
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Zafirlukast 20 mg b.i.d.
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Zileuton 1,200 mg b.i.d.
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Inhaled corticosteroid with or without long-acting beta agonist (dose varies depending on which product is used) (3)[A]
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Begin treatment with inhaled short-acting beta agonist before exercise.
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Cromolyn and nedocromil best used in conjunction with a short-acting beta agonist (3)[B]
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Tachyphylaxis to short-acting beta agonists can occur with daily use (3)[B].
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Maximize therapy of underlying asthma.
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Nonpharmacologic:
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For cold-weather athletes, wearing a mask to prewarm the inhaled air may help to reduce symptoms.
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Adequate warm-up (1)[B]:
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At least 15 min of warm-up at a level of exertion sufficient to provoke symptoms
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May take inhaler after warm-up is complete and rest for 15–30 min
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This can place the bronchospasm in a refractory period and reduce constriction during competition.
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Educate on proper use of inhalers and spacers.
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If allergies play a role in triggering asthma, then avoidance of triggers and consideration for immunotherapy (allergy shots)
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Follow-Up Recommendations
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If not responding to inhaled short-acting beta agonist, consider other diagnoses.
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Have patient return if use of short-acting beta agonist increases.
Patient Education
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All athletes with EIA should have a short-acting beta agonist inhaler with them during practices and games.
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All athletes should be taught proper use of an inhaler.
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Spacers can help to improve delivery of the inhaler medication.
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The athlete should know the difference between his or her controller and as-needed medication.
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Teach to avoid triggers.
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Consider allergy testing.
Prognosis
Good
Complications
Poorly controlled athletes with EIA can progress to airway remodeling that becomes unresponsive to short-acting beta agonists.
References
1. Parsons JP, Mastronarde JG. Exercise-induced bronchoconstriction in athletes. Chest. 2005;128:3966–3974.
2. Holzer K, Douglass JA. Exercise induced broncho-constriction in elite athletes: measuring the fall. Thorax. 2006;61:94–96.
3. Carlsen KH, Anderson SD, Bjermer L, et al. Treatment of exercise-induced asthma, respiratory and allergic disorders in sports and the relationship to doping: Part II of the report from the Joint Task Force of European Respiratory Society (ERS) and European Academy of Allergy and Clinical Immunology (EAACI) in cooperation with GA(2)LEN. Allergy. 2008;63:492–505.
4. Nelson HS, Weiss ST, Bleecker ER, et al. The Salmeterol Multicenter Asthma Research Trial: a comparison of usual pharmacotherapy for asthma or usual pharmacotherapy plus salmeterol. Chest. 2006;129:15–26.
Additional Reading
Schwartz LB, et al. Exercise-induced hypersensitivity syndromes in recreational and competitive athletes: a PRACTALL consensus report (what the general practitioner should know about sports and allergy). Allergy. 2008;63:953–961.
Storms WW. Review of exercise-induced asthma. Med Sci Sports Exerc. 2003;35:1464–1470.
Storms WW. Exercise-induced asthma: diagnosis and treatment for the recreational or elite athlete. Med Sci Sports Exerc. 1999;31:S33–S38.
CodesICD9
493.81 Exercise induced bronchospasm
Clinical Pearls
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1st-line treatment is a short-acting beta agonist before exercise.
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Avoid daily use of short-acting beta agonists because tachyphylaxis may develop. Have athlete use during high-intensity practice and competition.
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It is no longer recommended to use long-acting beta agonists without an inhaled corticosteroid.