eMedicine Specialties > Sports Medicine > Introductory Topics in Sports Medicine

Exercise-Induced Asthma

Anthony J Saglimbeni, MD, Staff Physician, Family Practice Residency, President, South Bay Sports and Preventive Medicine Associates; Private Practice; Team Internist, San Francisco Giants; Team Internist, West Valley College; Team Physician, Bellarmine College Prep; Team Physician, Presentation High School

Updated: Jun 15, 2009

Introduction

Background

Exercise-induced asthma (EIA) is a condition of respiratory difficulty that is triggered by aerobic exercise and lasts several minutes. Symptoms of EIA may resemble those of allergic asthma, or they may be much more vague and go unrecognized, resulting in probable underreporting of the disease.  

Exercise-induced urticaria, or anaphylaxis, is often presumed to be related to EIA, even though this condition is extremely rare and unrelated. EIA is related to histamine release.^1,2,3 Only 500-1000 cases of exercise-induced urticaria have been reported in the literature. In this condition, there is an early stage of exercise-related fatigue and itchiness, followed by early onset of urticaria and angioedema, which is initially mild.⁴ If progression occurs, there is choking, stridor, nausea, vomiting, and even hypotension. A late stage that is marked by headache may also occur. As implied by the alternative name of anaphylaxis, EIA can be life threatening; however, this can be prevented by exercise modification or avoidance of certain conditions (see Sport-Specific Biomechanics, below).
 
Related eMedicine articles:
Angioedema [in the Emergency Medicine section]
Asthma [in the Pulmonology section]
Exercise-Induced Anaphylaxis [in the Pediatrics section]
Urticaria [in the Allergy and Immunology section]

Asthma Resources from Medscape and eMedicine

• Asthma News and Articles
• Asthma Clinical Reference
• Asthma CME

Frequency

United States

EIA affects 12-15% of the population. Ninety percent of asthmatic individuals and 35-45% of people with allergic rhinitis experience EIA, but even when those with rhinitis and allergic asthma are excluded, a 3-10% incidence of EIA is seen in the general population.³

EIA seems to be more prevalent in some winter or cold-weather sports.⁵ Some studies have demonstrated rates as high as 35% or even 50% in competitive-caliber figure skaters, ice hockey players, and cross-country skiers.^6,7

Functional Anatomy

The problem in EIA occurs distal to the glottis, in the lower airway. Bronchoconstriction is involved that is distinguishable from laryngospasm, which can occur in other exercise-related conditions. One such example is the condition known as vocal cord dysfunction in which there is paradoxical narrowing of the vocal cords during inspiration, resulting in stridor that is often misconstrued as audible wheezing.^8,9 Normally, the vocal cords open with inspiration. (See also the eMedicine article Vocal Cord Dysfunction.)

Sport-Specific Biomechanics

EIA usually affects individuals who participate in sports that include an aerobic component. The condition can be seen in any sport, but EIA is much less common in predominantly anaerobic activities. This is likely due to the role of consistent and repetitive air movement through the airways (seen in aerobic sports), which affect airway humidity and temperature. EIA triggers an unknown biochemical and neurochemical pathway, resulting in the bronchospasm, which manifests as the symptoms of the disease.

Although the exact mechanism of EIA is unknown, there are 2 predominant theories as to how the symptom complex is triggered. One is the airway humidity theory, which suggests that air movement through the airway results in relative drying of the airway. This, in turn, is believed to trigger a cascade of events that results in airway edema secondary to hyperemia and increased perfusion in an attempt to combat the drying. The result is bronchospasm.

The other theory is based on airway cooling and assumes that the air movement in the bronchial tree results in a decreased temperature of the bronchi, which may also trigger a hyperemic response in an effort to heat the airway. Again, the result is a spasm in the bronchi.

Many authors think that there may be a combination of the above 2 theories that takes place, but the biochemical or physical pathways that mediate these responses are unclear. Evidence may even exist to support the idea that the resulting cascades are not the inflammatory pathways to which we attribute allergic asthma.

Likewise, certain sports and their environments predispose individuals with asthma to experience EIA. Sports played in cold and dry environments usually result in more symptom manifestation for athletes with this condition. On the other hand, when the environment is warm and humid, the incidence and severity of EIA decrease.

Clinical

History

Patients 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 :
  • Chest tightness or pain
  • Cough
  • Shortness of breath
  • Wheezing
  • Underperformance or poor performance on the field of play
  • Fatigue
  • Prolonged recovery time
  • Gastrointestinal (GI) discomfort
• Symptom denial may be seen due to the following:
  • Peer pressure
  • Embarrassment
  • Fear of losing position on the team
  • Misinterpretation as postexercise fatigue
• Contributing factors consist of the following:
  • Cool temperatures
  • Low-humidity environment
  • Poor air quality
  • High pollen counts
  • Coincident respiratory infection
  • Poor physical conditioning
• Exercise factors can include the following:
  • Aerobic exercise appears to be much more problematic than anaerobic exercise.
  • Duration of aerobic activity greater than 8-10 minutes provokes EIA.
  • High-intensity aerobic exercise also provokes EIA.
• Time interval between sessions of aerobic exercise
  • Refractory phase
    • Starts less than 1 hour after initial aerobic exercise
    • Lasts up to 3 hours
    • The refractory phase results in as little as one half the degree of bronchospasm as in the first episode.
    • Occurrence is unpredictable and intermittent
    • 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 and is more likely to occur if severe early exercise-induced bronchospasm (EIB) is present.
    • This late-phase response is usually less severe than the early response.

Physical

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.¹⁰ 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:
  • Skin (note any signs of atopic disease)
  • Head, ears, eyes, nose, and throat (note any evidence of acute infection, chronic infection, allergic/atopic disease)
  • Pharynx (note any mucus, cobblestoning, erythema)
  • Nose (note the presence of enlarged turbinates, erythema, congestion)
  • Sinuses (note the presence of tenderness)
  • Lungs (note the presence of rales, rhonchi, wheezes, a prolonged expiratory phase)
  • Heart (note the presence of murmurs, an irregular rhythm)

Causes

The causes of EIA can be divided into the categories of medical, environmental, and drug related. Eliminating some causes can diminish—but may not eliminate—the athlete's symptoms. EIA may also exist without the presence of any of these causes.

• Medical
  • Poorly controlled asthma results in increased patient symptoms with exercise.
  • Maximizing control of the patient's baseline asthma, when present, is critical in the treatment of EIA.¹
  • Poorly controlled allergic rhinitis also results in increased patient symptoms with exercise.
  • Secretions resulting from hay fever can aggravate both allergic asthma and EIA.
  • Viral, bacterial, and other forms of upper respiratory infections also aggravate the symptoms of EIA.
    • Controlling the secretions of these illnesses, as with allergic rhinitis, can make the EIA symptoms much more tolerable.
• Environmental
  • Excess of pollens or other allergens in the air can exacerbate the allergic and exercise-induced forms of asthma.
    • Pollutants in the air are irritants to the airways and can lower the threshold for symptomatic bronchospasm.
  • The chemicals used in certain sports for environmental maintenance can predispose individuals to wheezing and worsen EIA symptoms. These chemicals include the following:
    • Chlorination in pools
    • Insecticides and pesticides used to maintain playing fields
    • Fertilizers and herbicides used to maintain playing fields
    • Paints and other decorative substances to enhance the appearance of playing fields
• Drugs – Asthmogenic agents include the following:
  • Beta-blockers (β- blockers)
  • Aspirin
  • Nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Diuretics
  • Zanamivir

Differential Diagnoses

Anxiety
Hyperventilation Syndrome
Vocal Cord Dysfunction

Other Problems to Be Considered

Deconditioning syndrome
Seasonal asthma 
Upper airway obstruction

Workup

Laboratory Studies

• In general, EIA is diagnosed clinically and may not need any further laboratory studies, imaging, or other tests and procedures. Laboratory evaluation is reserved for equivocal cases, for treatment failures, and to narrow the differential diagnosis when it seems reasonable. Therefore, consider testing to evaluate cardiac conditions, vocal cord and upper airway obstructive conditions, allergic conditions, and psychiatric conditions.
• A complete blood cell count and differential ("CBC with diff") can help in the assessment of the likelihood of infection by analysis of the patient's white blood cells and by evaluation of the eosinophil counts (for allergy).
• An erythrocyte sedimentation rate (ESR) result may help in the evaluation of inflammatory and infectious conditions.
• Assessing the immunoglobulin E (IgE) count helps in determining the likelihood of allergic disease.
• Skin allergen testing or a radioallergosorbent test (RAST) can be used to help identify specific allergens to promote patient avoidance or immunotherapy, if indicated. Either method has been used extensively in atopic workups. In young children, RAST testing may be preferable owing to the relative ease of administration, but this is a less specific test, and therefore, skin testing may be preferred in general.
• Thyrotropin levels can be used to help evaluate the potential of patient thyroid dysfunction in the likelihood that anxiety is mimicking the symptoms of asthma.
• If the diagnosis is uncertain, performing a nasal swab for the presence of eosinophils is helpful in identifying the role of allergic rhinitis.
• Sputum analysis and culture can be used to help identify the presence of infection and treatment options for strains of resistant organisms.

Imaging Studies

• Imaging studies are often not indicated in the evaluation of routine EIA, but they may be useful for evaluating other possibilities in the differential diagnosis.
• Chest radiograph
  • To evaluate for signs of chronic lung disease (eg, hyperexpansion, scarring, fibrosis, hilar adenopathy)
  • To evaluate for congestive heart failure and/or valvular heart disease (eg, chamber enlargement, pulmonary edema, vascular or valvular calcification)
  • To evaluate for a foreign body
• Lateral neck radiographs/soft-tissue penetration to evaluate the upper airway for a foreign body or obstruction
• Echocardiography to evaluate for cardiac valvular abnormality or global contractile function

Other Tests

• Echocardiography can also be used to evaluate dysrhythmia, cardiomegaly, or other heart disease that may manifest during exercise.

Procedures

• Various challenge tests exist that can be used to formalize the diagnosis of EIA. A formal diagnosis is often not critical, clinically, but in recent years, the US Olympic Committee has required a positive challenge test to be documented for an athlete to qualify for the use of controlled substances that aid in ameliorating the symptoms of EIA. This requirement has resulted in new studies that have been used to validate some of these assessment tools, whether they are field challenges, treadmill testing, or new techniques such as eucapnic voluntary hyperventilation (EVH).^7,10,11
• Treadmill exercise challenges with preexercise and postexercise pulmonary functions
  • This type of testing formalizes an aerobic challenge and provides an objective measure of the degree of bronchospasm that results from the exercise. The results can help the physician to clarify the diagnosis and to enforce the treatment; the results can also be used to evaluate success of the treatment.
  • Before the exercise challenge, the patient's baseline pulmonary function levels should be obtained (preferably forced expiratory volume in 1 second [FEV₁], forced vital capacity [FVC], or FEV₁/FVC, or, less ideally, peak expiratory flow rate [PEFR]). The exercise challenge involves exercising the athlete on a treadmill until his or her heart rate reaches 70-85% of the maximum predicted heart rate. This is maintained for 6-10 minutes, at which time the exercise is stopped. Pulmonary function levels are measured every 2-10 minutes for 15-30 minutes and then compared with the baseline measurements.
  • Any drop from the baseline that is greater than or equal to 10%, on any postexercise measurement, indicates EIA. Severity of disease can be classified as follows:
    • Mild – Decrease of 10-20% from baseline
    • Moderate – Decrease of 20-40% from baseline
    • Severe – Decrease of greater than 40% from baseline
• An informal exercise challenge can be substituted for the above procedure, but without monitoring the heart rate, the level of work is not reliable.
• Laryngoscopy can be performed to evaluate for foreign body or other obstruction in the upper airway.
• Postexercise laryngoscopy can be used to evaluate for vocal cord dysfunction, a condition often mistaken for EIA. Vocal cord dysfunction manifests as stridor with exercise due to paradoxical contraction of the vocal cords with inspiration; this condition can be evaluated via laryngoscopy after an exercise challenge.
• Pulmonary function testing can be used to evaluate baseline pulmonary function or allergic asthma and to categorize pulmonary function as obstructive or restrictive disease.
• Bronchoprovocation testing, as used with general asthma, methacholine, histamine, or cold air challenges, can be used to assess asthma. However, if the results are positive, they are indicative of asthma in general, not specifically EIA.
• EVH is a new technique believed to be more sensitive and more accurate for diagnosing EIA.^7,11 Furthermore, EVH can be applied in a laboratory setting and altered to mimic the environmental conditions of the sport in question.

Treatment

Acute Phase

Medical Issues/Complications

Although rare, as with any asthma attack, progression of EIA can result in status asthmaticus and even death. Treatment for this condition should be provided immediately and the situation taken seriously.

Consultations

On the playing field, consultation is rarely available and is not needed in the acute EIA attack; however, access to the emergency medical system should be readily available.

Other Treatment

Treatment of the athlete who is experiencing an acute attack of EIA is the same as in any asthma attack situation and includes the following:

• Immediately remove the patient from competition or play.
• Provide immediate administration of a rapid onset, short-acting β₂ -agonist (eg, albuterol); this has the highest therapeutic yield. The usual dose is 2 puffs of albuterol via a metered dose inhaler (MDI).
  • If the patient's response is not satisfactory, transportation to an emergency facility should be initiated because the EIA attack may escalate.
  • If available, the use of a spacer device can help to transport the medication to the area of greatest need, especially when an athlete is distracted in the midst of competition or anxious from dyspnea and unable to concentrate.
• If the initial treatment fails or is unavailable, immediate transfer of the patient to an acute care facility should occur. Subcutaneous epinephrine can be administered in such life-threatening situations.

Recovery Phase

Medical Issues/Complications

If the initial response to treatment was adequate, patient observation and monitoring need to continue for several hours in case of a relapse.

Consultations

If patient relapse is immediate, transportation to an emergency facility should be initiated.

Other Treatment (Injection, manipulation, etc.)

If mild, residual symptoms persist in the patient after relief of the acute symptoms, a repeat administration of albuterol is advisable; the recommended dosing interval is 4 hours.

Maintenance Phase

Medical Issues/Complications

Long-term treatment of EIA is prevention of the condition (see Medication).¹

Other Treatment

Nonpharmacologic measures can also be taken in the treatment of EIA.

• Sports selection – It can be helpful to guide an athlete toward the performance of sports in environments that are less likely to cause bronchospasm. If the athlete has a choice, he or she can choose a time or place to exercise where the air is warmer and the humidity is higher. Likewise, a flexible athlete can change sports to be more active in these sorts of environments (eg, changing from running to swimming automatically increases the humidity of the environment). As indicated earlier, focusing on sports with less prolonged aerobic demands (eg, sprinting, weight lifting, baseball, football) is better tolerated by affected athletes.
• Breathing and warm-up techniques:
  • Altering breathing techniques – A change from predominant mouth breathing to nasal breathing can result in less bronchospasm with the performance of an activity because the inhaled air is both warmed and humidified.
  • The coordination and timing of competition with medication use can also maximize exercise performance with regard to bronchospasm. To minimize the likelihood of bronchospasms, the athlete can time the warm-up so that the competition coincides with a refractory phase. This is most likely to occur by initiating a 15-30 minute warm-up followed by a 15-minute rest period, at which time the medication is administered. This entire period should be timed to result in commencement of the competition 15-30 minutes after medication administration.

Medication

The optimal treatment for EIA is to prevent the onset of symptoms. After controlling the patient's underlying and contributing factors (eg, respiratory infection, allergy, allergic asthma), a combination of drugs can be used to prevent EIA.¹ The basis of treatment is with preexercise short-acting β₂ -agonist administration.¹ A role also exists for long-acting β₂ -agonists and mast cell stabilizers. Antileukotriene drugs have been shown to be effective as well.^12,13 Traditional asthma medications (eg, corticosteroids, theophylline) have less of a role in the treatment of pure EIA. There is ongoing investigation regarding other agents (eg, heparin, calcium-channel blockers, diuretics).

Beta2-agonists

These agents are used for prophylactic bronchodilation to prevent the onset of symptoms with exercise and have been shown to have a 90% efficacy.

Albuterol (Proventil, Ventolin)

DOC and first-line agent. β ₂ -agonist for bronchospasm that is refractory to epinephrine. Relaxes bronchial smooth muscle by action on β ₂ -receptors with little effect on cardiac muscle contractility.

Dosing

Adult

2 puffs via metered dose inhaler 15-30 min preexercise

Pediatric

1-2 puffs via metered dose inhaler 15-30 min preexercise

Interactions

Caution with other sympathomimetics, MAOIs, tricyclic antidepressants, other agents that decrease potassium

Contraindications

Documented hypersensitivity; tachyarrhythmias; hypokalemia

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

May cause jitteriness and tachycardia; caution with hypokalemia from repetitive and frequent use

Salmeterol (Serevent)

By relaxing the smooth muscles of the bronchioles in conditions that are associated with bronchitis, emphysema, asthma, or bronchiectasis, salmeterol can relieve bronchospasms. Effect may also facilitate expectoration.

Adverse effects are more likely to occur when this agent is administered at high or more frequent doses than recommended; the incidence of side effects is then higher.

Dosing

Adult

2 puffs via metered dose inhaler 30-45 min preexercise or bid

Pediatric

1-2 puffs via metered dose inhaler 30-45 min preexercise or bid

Interactions

Caution with other sympathomimetics, MAOIs, tricyclic antidepressants

Contraindications

Documented hypersensitivity; tachyarrhythmias; hypokalemia

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm; long-acting β ₂ -agonists may cause more tachyphylaxis than short-acting agents.

Mast cell stabilizers

These agents are 70-80% effective in preventing bronchospasm during exercise. An additive effect is noted when used in combination with albuterol.

Cromolyn sodium (Intal, Nasalcrom)

First- or second-line agent in the prevention of EIA.

Dosing

Adult

2 puffs via metered dose inhaler 30-45 min preexercise

Pediatric

1-2 puffs via metered dose inhaler 30-45 min preexercise

Interactions

None reported

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm; avoid use with isoproterenol during pregnancy.

Inhaled corticosteroids

These agents provide no bronchodilatory effect but are useful in controlling the underlying inflammation of allergic asthma.

Flunisolide (AeroBid Oral Aerosol Inhaler, Nasalide Nasal Aerosol)

Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing capillary permeability. Does not depress the hypothalamus. Considered a third-line agent.

Dosing

Adult

2-4 inhalations qd/qid; varies with preparation

Pediatric

<6 years: Some preparations are contraindicated
>6 years: 1-4 inhalations qd/qid; varies with preparations

Interactions

None reported

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm.

Triamcinolone acetonide (Azmacort)

Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing capillary permeability. Considered a third-line agent.

Dosing

Adult

2-4 inhalations qd/qid; varies with preparation

Pediatric

<6 years: Some preparations are contraindicated
>6 years: 1-4 inhalations qd/bid/tid/qid; varies with preparations

Interactions

None reported

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm; do not exceed recommended doses.

Beclomethasone dipropionate (Beclovent, Beconase, Vancenase, Vanceril)

Inhibits bronchoconstriction mechanisms; produces direct smooth muscle relaxation; may decrease number and activity of inflammatory cells, in turn decreasing airway hyperresponsiveness. Considered a third-line agent.

Dosing

Adult

2-4 inhalations qd/qid; varies with preparation

Pediatric

<6 years: Some preparations are contraindicated
>6 years: 1-4 inhalations qd/qid; varies with preparations

Interactions

Coadministration with ketoconazole may increase plasma levels but do not appear to be clinically significant

Contraindications

Documented hypersensitivity, bronchospasm, status asthmaticus, other types of acute episodes of asthma

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm.

Xanthine derivatives

Xanthine derivatives have been used in allergic asthma for their bronchodilatory and anti-inflammatory properties; however, these agents have multiple side effects. Therefore, monitoring for nontoxic levels is necessary.

Theophylline (Aminophylline, Theo-24, Theolair)

Potentiates exogenous catecholamines, stimulates endogenous catecholamine release and diaphragmatic muscular relaxation, which in turn stimulates bronchodilation.

For bronchodilation, near-toxic (>20 mg/dL) levels are usually required.

Dosing

Adult

5.6 mg/kg loading dose (based on aminophylline) IV over 20 min, followed by maintenance infusion of 0.1-1.1 mg/kg/h

Pediatric

6 weeks to 6 months: 0.5 mg/kg/h loading dose IV in first 12 h (based on aminophylline), followed thereafter by maintenance infusion of 12 mg/kg/d; may administer continuous infusion by dividing total daily dose by 24 h

6 months to 1 year of age: 0.6-0.7 mg/kg/h, loading dose IV in first 12 h, followed by maintenance infusion of 15 mg/kg/d; may administer as continuous infusion, as above

>1 year: Administer as in adults

Interactions

Aminoglutethimide, barbiturates, carbamazepine, ketoconazole, loop diuretics, charcoal, hydantoins, phenobarbital, phenytoin, rifampin, isoniazid, and sympathomimetics may decrease effects of theophylline; theophylline effects may increase with allopurinol, β -blockers, ciprofloxacin, corticosteroids, disulfiram, quinolones, thyroid hormones, ephedrine, carbamazepine, cimetidine, erythromycin, macrolides, propranolol, and interferon.

Contraindications

Documented hypersensitivity; patients with uncontrolled arrhythmias, peptic ulcers, hyperthyroidism, and uncontrolled seizure disorders

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in patients with peptic ulcer disease, hypertension, tachyarrhythmias, hyperthyroidism, and compromised cardiac function; do not inject IV solution >25 mg/min; patients with pulmonary edema or liver dysfunction are at greater risk of toxicity because of reduced drug clearance.

Leukotriene receptor antagonists

Leukotriene receptor antagonists can be used as adjuncts in cases of incompletely controlled EIA with the use of other agents; however, leukotriene receptor antagonists should be reserved for more frequent and persistent cases of EIA rather than for intermittent cases. Leukotriene receptor antagonists should not to be used alone for the treatment of EIA.

Zafirlukast (Accolate)

Inhibits effects by the leukotriene receptor, which has been associated with asthma, including airway edema, smooth muscle contraction, and cellular activity associated with the symptoms. Third-line agent and used as adjunct only.

Dosing

Adult

20 mg PO bid

Pediatric

10 mg PO bid

Interactions

Erythromycin and theophylline decrease serum levels; aspirin increases levels of zafirlukast; zafirlukast increases toxicity of warfarin.

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm; may cause liver inflammation; not for use as monotherapy in the management of EIB
Neuropsychiatric events have been reported, and following further FDA evaluation, the prescribing information has been updated to include case reports during postmarketing surveillance that include agitation, aggression, anxiousness, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior (including suicide), and tremor

Montelukast (Singulair)

Inhibits the leukotriene receptor effects associated with asthma, including airway edema, smooth muscle contraction, and cellular activity associated with the symptoms. Third-line agent and used as an adjunct only. European studies have suggested an improvement in gas exchange versus β ₂ -agonist medication.

Dosing

Adult

10 mg PO at least 2 h before exercise; do not repeat dose within 24 h

Pediatric

<15 years: Not established; some pediatric subspecialists recommend 5 mg PO qd
> 15 years: Administer as in adults

Interactions

Phenobarbital and rifampin reduce effects.

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Not indicated to reverse acute asthma attacks; not for use as monotherapy in the management of EIB; use appropriate short-acting, inhaled β ₂ -agonist for exacerbations; if already taking montelukast daily (eg, chronic asthma, allergic rhinitis), do not take an additional dose to prevent EIB; administration for chronic asthma has not been established to prevent acute EIB; chewable tab contains phenylalanine: caution in patients with phenylketonuria
Neuropsychiatric events have been reported, and following further FDA evaluation, the prescribing information has been updated to include case reports during postmarketing surveillance that include agitation, aggression, anxiousness, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior (including suicide), and tremor

Zileuton (Zyflo)

Inhibits leukotriene formation, which in turn decreases neutrophil and eosinophil migration, neutrophil and monocyte aggregation, leukocyte adhesion, capillary permeability, and smooth muscle contractions. Third-line therapy and used as an adjunct only.

Dosing

Adult

600 mg PO qid

Pediatric

Not established

Interactions

Monitor drugs that are metabolized by cytochrome p3A4; potentiates theophylline, warfarin, and propranolol

Contraindications

Documented hypersensitivity; patients with active liver disease or transaminase elevation greater than or equal to 3 times the upper limit of the normal value

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm; monitor liver enzymes; neuropsychiatric events have been reported, and following further FDA evaluation, the prescribing information has been updated to include case reports during postmarketing surveillance that include agitation, aggression, anxiousness, dream abnormalities, hallucinations, depression, insomnia, irritability, restlessness, suicidal thinking and behavior (including suicide), and tremor

Adrenergic agonists

Adrenergic agonists are used in the emergency treatment of life-threatening situations, when β-agonists are unavailable or treatment with β-agonists has failed.

Epinephrine (Adrenalin, Bronitin, EpiPen, Primatene Mist)

Has α -agonist effects that include increased peripheral vascular resistance, reversed peripheral vasodilatation, systemic hypotension, and vascular permeability. β -agonist effects of epinephrine include bronchodilation, chronotropic cardiac activity, and positive inotropic effects. Indicated in the emergency treatment of bronchospasm.

Dosing

Adult

0.2-1 mg SC q4h prn

Pediatric

0.01 mg/kg SC q4h prn; not to exceed 0.5 mg

Interactions

May potentiate the pressor effects of tricyclic antidepressants, furazolidone, antihistamines, levothyroxine, β- blockers, and guanethidine; epinephrine may be antagonized by nitrites and α-b lockers; should avoid digitalis and other arrhythmia-producing agents

Contraindications

Documented hypersensitivity; cardiac arrhythmias; angle-closure glaucoma; local anesthesia in areas such as fingers or toes because vasoconstriction may produce sloughing of tissue; during labor (may delay second stage of labor)

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in elderly patients and in patients with prostatic hypertrophy, hypertension, cardiovascular disease, diabetes mellitus, hyperthyroidism, and cerebrovascular insufficiency; rapid IV infusions may cause death from cerebrovascular hemorrhage or cardiac arrhythmias

Follow-up

Return to Play

The severity of an EIA attack varies greatly. Although cases of respiratory arrest and even death have been reported, the usual scenario is of a mild respiratory difficulty during play, which either spontaneously resolves or immediately responds to inhaled albuterol. Oftentimes, the athlete self-medicates and never leaves play or alerts the trainer or doctor. Although no clear-cut guidelines exist, a player who is removed from play for an asthma attack should be kept out of play until his or her respiration has normalized. This should occur within 5-10 minutes of medication administration. The athlete should be monitored closely for signs of relapse over the next several hours. If the symptoms do not completely resolve with sideline medication, the athlete should not return to play and should be referred for further treatment. Depending on the severity of the patient's symptoms, this may require transportation via ambulance.

Complications

Complications of an untreated asthma attack include status asthmaticus, respiratory failure, and even death. More commonly, an anxiety attack can be precipitated secondary to dyspnea.

Prevention

The optimal treatment of EIA is to prevent the onset of symptoms. See the Medication section for a discussion of drugs used to prevent EIA.

Prognosis

The prognosis is excellent for athletes with asthma. With proper interventions, most symptoms can be prevented, and performance should not be limited by EIA if this condition is treated properly. Newly diagnosed young athletes need to be educated that this condition should not be perceived as an insurmountable disability. Using examples of the numerous elite athletes (eg, Jackie Joyner-Kersee [perhaps the world's greatest athlete]; Amy Van Dyken [Olympic swimmer]; Jerome Bettis [former running back for the Pittsburgh Steelers]) with this condition can help young impressionable athletes continue in their endeavors without fear of failure or medical distress.

Education

Patient education is a critical part of the treatment of EIA. Once the diagnosis is made, athletes should be encouraged to continue in their activities with the reassurance that proper treatment can allow for an unhampered performance for most individuals. In addition to reassurance, it is also important to teach individuals to recognize the signs of an impending attack. Once recognized, individuals should be taught to remove themselves from the aggravating activity and initiate treatment as necessary. This includes education about the proper choice of agents to abort an acute attack (ie, albuterol), but not cromolyn, salmeterol, or an inhaled steroid. Teaching the proper mechanics of inhalant medication administration is also important, along with, if needed, teaching and demonstrating the proper use of a spacer device to the patient; without the proper mechanics in using such devices, the medication does not reach the area of pathology and does not benefit the athlete.

For excellent patient education resources, visit eMedicine's Asthma Center. Also, see eMedicine's patient education articles Asthma, Asthma FAQs, and Exercise-Induced Asthma.

Miscellaneous

Medicolegal Pitfalls

• Downplaying of symptoms: The common pitfalls occur with downplaying of symptoms or patient complaints. Education of the coaching staff is crucial because coaches need to know that shortness of breath in athletes does not always indicate poor conditioning and that the consequences of ignoring an asthma attack can be serious.
• Missed diagnosis: The physician, trainer, or other medical staff must always consider bronchospasm in athletes with the previously described complaints. A high index of suspicion diminishes the possibility of missed diagnoses. A thorough knowledge of the differential diagnosis (see Differentials) and how to work up the possibilities are also important (see Workup).

Special Concerns

• Pregnancy: Although most of the commonly used drugs are in pregnancy category C, these agents are often used for asthma, which is a common condition of pregnancy.
• Pediatric population: Many of the agents used for asthma are not indicated for children younger than 2 years; other agents are not indicated for children younger than 6 years. However, these medications have been used successfully for decades in the management of childhood asthma and should be used for children with EIA.
• Other/general: The highly driven, high-performing adolescent athlete, especially the female athlete, is at high risk for vocal cord dysfunction. This condition can be confused with EIA but does not respond to the same treatment. Professionals caring for athletes must keep a high index of suspicion for vocal cord dysfunction.

References

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8. Wilson JJ, Wilson EM. Practical management: vocal cord dysfunction in athletes. Clin J Sport Med. Jul 2006;16(4):357-60. [Medline].

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12. Storms W. Update on montelukast and its role in the treatment of asthma, allergic rhinitis and exercise-induced bronchoconstriction. Expert Opin Pharmacother. Sep 2007;8(13):2173-87. [Medline].

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19. National Asthma Education and Prevention Program. Expert Panel Report: Guidelines for the Diagnosis and Management of Asthma - Update on Selected Topics 2002. Bethesda, Md: National Institutes of Health and National Heart, Lung, and Blood Institute; June 2003. NIH publication no. 02-5074. [Full Text].

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Keywords

EIA, exertional asthma, exercise-induced bronchospasm, EIB, asthma, exercise-induced urticaria, allergic rhinitis, bronchoconstriction, exercise-related respiratory symptoms, wheezing, chest tightness, shortness of breath, dyspnea, difficulty breathing, aerobic exercise, environmental factors, allergic asthma, asthmogenic agents

Contributor Information and Disclosures

Author

Anthony J Saglimbeni, MD, Staff Physician, Family Practice Residency, President, South Bay Sports and Preventive Medicine Associates; Private Practice; Team Internist, San Francisco Giants; Team Internist, West Valley College; Team Physician, Bellarmine College Prep; Team Physician, Presentation High School
Disclosure: Nothing to disclose.

Medical Editor

Joseph P Garry, MD, FACSM, FAAFP,, Director of Sports Medicine and Sports Medicine Fellowship, Associate Professor of Family Medicine and Exercise and Sport Science, Department of Family Medicine, East Carolina University Brody School of Medicine
Joseph P Garry, MD, FACSM, FAAFP, is a member of the following medical societies: American Academy of Family Physicians, American College of Sports Medicine, American Heart Association, American Medical Society for Sports Medicine, and North American Primary Care Research Group
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Russell D White, MD, Professor of Medicine, Department of Community and Family Medicine, University of Missouri-Kansas City School of Medicine, Truman Medical Center Lakewood
Disclosure: Nothing to disclose.

CME Editor

Jon B Whitehurst, MD, Clinical Instructor of Surgery, University of Illinois College of Medicine; Partner and Executive Board Member, Rockford Orthopedic Associates; Orthopedic Chairman, Rockford Memorial Hospital
Jon B Whitehurst, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and Arthroscopy Association of North America
Disclosure: Nothing to disclose.

Chief Editor

Craig C Young, MD, Professor, Departments of Orthopedic Surgery and Community and Family Medicine, Medical Director of Sports Medicine, Sports Medicine Fellowship Director, Medical College of Wisconsin
Craig C Young, MD is a member of the following medical societies: American Academy of Family Physicians, American College of Sports Medicine, American Medical Society for Sports Medicine, Phi Beta Kappa, and Wilderness Medical Society
Disclosure: Nothing to disclose.

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