Exercise-Induced Asthma

[David Baxter PhD]

Exercise-Induced Asthma

Overview
Asthma is a chronic (long-term, ongoing) inflammation (irritation) of the breathing passages (bronchi) of the lungs. Asthma is characterized by sudden attacks or periods of bothersome or severe symptoms separated by periods of mild symptoms or no symptoms at all. Asthma is an inflammatory reaction that is triggered by external factors or specific situations. When a person with asthma is exposed to one of his or her triggers, the inflammation worsens and symptoms ensue.

• The list of triggers is long and varied.
• Each individual with asthma has his or her own specific trigger or set of triggers.
• These triggers generally have something to do with the way we breathe or the condition of the atmosphere we breathe in.
• Triggers include contaminants in the air, such as smoke, pollution, vapors, dust, or other particles; respiratory infections, such as colds and flu (viruses); allergens in the air, such as molds, animal dander, and pollen; extremes of temperature or humidity; and emotional stress.
• Exercise is a common trigger of asthma attacks.

Exercise can even induce an asthma attack in people who have no other triggers and do not experience asthma under any other circumstances.

• People with exercise-induced asthma are believed to be more than usually sensitive to changes in the temperature and humidity of the air.
• When you are at rest, you breathe through your nose, which serves to warm and humidify the air you breathe in to make it more like the air in the lungs.
• When you are exercising, you breathe through your mouth, and the air that hits your lungs is colder and drier. The contrast between the warm air in the lungs and the cold inhaled air can trigger an attack.

Once the attack is triggered, the airways begin to swell (bronchospasm) and secrete large amounts of mucus.

• The swelling and extra mucus partially block or obstruct the airways. This makes it more difficult to push air out of your lungs (exhale).
• Because of this, asthma is referred to as a chronic obstructive pulmonary disease (COPD), like emphysema and chronic bronchitis.

Unlike other types of COPD, asthma is reversible. It cannot be cured, but it can be controlled by medication.

• With appropriate treatment, almost everyone with exercise-induced asthma can enjoy the mental and physical benefits of regular exercise.
• The large number of elite athletes who have asthma attests to the effectiveness of asthma medication.
• Whether you walk around your neighborhood or run marathons, asthma doesn't need to stop you from reaching your exercise goals.

Causes of Exercise-Induced Asthma
Asthma has two components: the underlying chronic inflammation and the periodic attacks. We do not know for certain what causes the underlying inflammation. What we do know is that the tendency to have asthma runs in families and that some people are born with the tendency to have asthma.

We do know what causes asthma attacks ?exposure to a trigger. In exercise-induced asthma, that trigger is mouth breathing during exercise. The attack is similar in many ways to an allergic reaction.

• An allergic reaction is a response by the body's immune system to an "invader." That invader can be a substance or anything that the body senses as "different."
• When the cells of the immune system sense an invader, they set off a series of reactions that help fight off the invader.
• It is this series of reactions that causes the production of mucus and bronchospasms. These responses cause the symptoms of as asthma attack.
• Because asthma is a type of allergic reaction, it is sometimes called reactive airway disease.

Sports and games that require continuous activity or are played in cold weather are most likely to trigger an asthma attack.

• Long-distance running
• Basketball
• Soccer
• Hockey (ice and field)
• Cross-country skiing

Sports that are less likely to trigger an asthma attack are those that require short bursts of activity interspersed with breaks.

• Walking
• Recreational biking (not racing)
• Hiking
• Swimming
• Short-distance running and track/field events
• Baseball or softball
• Golfing
• Football
• Volleyball
• Wrestling
• Gymnastics
• Downhill skiing

Exercise-Induced Asthma Symptoms
Symptoms usually begin about 5-20 minutes after beginning to exercise. The symptoms usually peak about 5-10 minutes after stopping exercise, then gradually diminish. The symptoms are often gone within an hour, but they may last longer. Symptoms include one or a combination of the following:

• Coughing
• Wheezing
• Chest tightness
• Chest pain
• Prolonged shortness of breath
• Extreme fatigue

Symptoms may be more subtle in children.

• Children may complain of not being able to keep up with peers in games and sports.
• They may say they don't like games or avoid participating.
• This can lead to problems with socialization or self-esteem in some children.

When to Seek Medical Care
If you think you or your child may have exercise-induced asthma, promptly make an appointment with your health care provider.

If you or your child has exercise-induced asthma, you should have an action plan worked out in advance with your health care provider. This plan should include instructions on how to prevent an attack while exercising, what to do when an asthma attack occurs, when to call the health care provider, and when to go to a hospital emergency department.

The following is an example of an action plan in case of an exercise-induced attack:

• Take 2 puffs of an inhaled beta2-agonist (a rescue medication), with 1 minute between puffs. If there is no relief, take an additional puff every 5 minutes. If there is no response after 8 puffs, which is 40 minutes, your health care provider should be called.
• Your provider should also be called if you have an asthma attack when you are already taking oral or inhaled steroids or if your inhaler treatments are not lasting 4 hours.
• These are general guidelines only. If your provider recommends another plan for you, follow that plan.

Although asthma is a reversible disease, and treatments are available, people can die from a severe asthma attack.

• If you are having an asthma attack and have severe shortness of breath or are unable to reach your health care provider in a short period of time, you must go to the nearest hospital emergency department.
• Do not drive yourself to the hospital. Have a friend or family member drive. If you are alone, immediately call 911 for emergency medical transport.

Exams and Tests
If you are having an asthma attack, your health care provider (whether your primary care provider or an emergency department physician) will ask you questions about your symptoms, medical history, and medications. Answer as completely as you can. He or she will also examine you and observe you as you breathe.

He or she will assess the severity of the attack. Attacks are usually classified as mild, moderately severe, or severe. This assessment is based on several factors.

• Symptom severity and duration
• Degree of airway obstruction
• Extent to which the attack is interfering with regular activities

If you have had symptoms and are seeking medical care afterward, the health care provider will ask questions and perform tests to search for and rule out other causes of the symptoms. The evaluation will almost certainly include tests of how well you can breathe at rest and may include tests during exertion. These tests are done at rest, after 6-8 minutes of exercise, and then at regular intervals until at least 30 minutes after you have stopped exercising. Proper diagnosis is essential to ensure that the most appropriate treatment is given.

Measurements of how well you are breathing include the following:

• Spirometry: The spirometer is a device that measures how much air you can exhale and how forcefully you can breathe out. The test may be done before and after you inhale a medication. Spirometry is a good way to see how much your breathing is impaired during an attack. This test must be done in the medical office; you may exercise on a treadmill or stationary bicycle.
• Peak flow meter: This is another way of measuring how forcefully you can breathe out during an attack. This device is small and portable and can be used "in the field." This allows testing after 6-8 minutes of your usual activity.
• Oximetry: A painless probe, called a pulse oximeter, may be placed on your fingertip to measure the amount of oxygen in your bloodstream.

No blood test can pinpoint the cause of asthma.

• Your blood may be checked for signs of an infection that might be contributing to the symptoms.
• In severe attacks, it may be necessary to sample blood from an artery to determine exactly how much oxygen and carbon dioxide are present in your body.

A chest x-ray may also be taken. This is mostly to rule out other conditions that can cause similar symptoms.

Treatment of Exercise-Induced Asthma
Since exercise-induced asthma is a chronic disease, treatment goes on for a very long time. Some people have to use medication for the rest of their lives. The best way to improve your condition and live your life on your terms is to learn all you can about your asthma and what you can do to make it better.

• Become a partner with your health care provider and his or her support staff. Use the resources they can offer ?information, education, and expertise ?to help yourself.
• Follow the treatment recommendations of your health care provider. Understand your treatment. Know what each drug does and how it is used.
• See your health care provider as scheduled.
• Promptly report any changes or worsening of your symptoms.
• Report any side effects you are having with your medications.

The goals of treatment are as follows:

• To prevent attacks
• To carry on with normal activities
• To maintain normal or near-normal lung function
• To have as few side effects of medication as possible

Self-Care at Home
Work with your health care provider to develop an action plan. Follow your treatment plan closely to avoid an asthma attack during and after exercising. If you do have an asthma attack, the action plan will help you control the attack and make the decision about when to seek medical care.

If you should have an asthma attack, move to the next step of your action plan. Keep the following tips in mind:

• Take only the medications your health care provider has prescribed for your asthma. Take them as directed.
• If the medication is not working, do not take more than you have been directed to take. Overusing asthma medications can be dangerous.
• Do not take cough medicine. These medicines do not help asthma and may cause unwanted side effects.
• Aspirin and nonsteroidal anti-inflammatory drugs, such as ibuprofen, can cause asthma to worsen in certain individuals. These medications should not be taken without the advice of your health care provider.
• Do not use nonprescription inhalers. These contain a very short-acting inhaler that may not last long enough to relieve an asthma attack and may cause unwanted side effects.
• Do not take any nonprescription preparations, herbs, or supplements, even if they are completely "natural," without talking to your health care provider first. Some of these may have unwanted side effects or interfere with your medications.
• Be prepared to go on to the next step of your action plan if necessary.

If you think your medication is not working, let your health care provider know right away.

Medical Treatment
Most people with exercise-induced asthma, if exercise is their only trigger, do not have to take medication every day (unless they exercise every day). Medication is taken before exercising, each time you exercise, to prevent an attack.

• The medications most widely used by people with exercise-induced asthma are the short- and long-acting beta2-agonist bronchodilator inhalers.
• Other preventive medications are inhaled cromolyn sodium and oral leukotriene inhibitors.

Precautions that may help reduce your chance of having an asthma attack include the following:

• Spending time warming up before starting strenuous exertion can help prevent asthma symptoms. Similarly, a gradual cooling down after exertion can prevent symptoms after exertion.
• Avoid exertion when you have a respiratory tract infection, such as a cold, flu, or bronchitis.
• Avoid exertion in extremely cold weather.
• If you smoke, quit.
• If you have allergies, avoid exertion when a reaction is likely to be triggered, as when the pollen count is high or the pollution index is high.

If you have frequent exercise-induced asthma attacks despite using preventive medication, or if you have attacks when you are not exercising, you need to see your health care provider right away. You may need to use daily medication to control the underlying inflammation that is causing your frequent attacks.

Together, you and your health care provider will develop an action plan for you in case of asthma attack. The action plan will include the following:

• How to use rescue medication
• What to do if the rescue medication does not work right away
• When to call the health care provider
• When to go directly to a hospital emergency department

Medications
Inhaled, short-acting beta2-agonist bronchodilators are the medications most often used to prevent asthma attacks in exercise-induced asthma.

• Use 2-4 puffs 5-30 minutes before exercising. The medication works best if taken just before exercising.
• This class of drugs is chemically related to adrenaline, a hormone produced by the adrenal glands.
• Inhaled beta2-agonists work rapidly (within minutes) to open the breathing passages. They relax the muscles of the breathing passages, dilating the passages and decreasing the resistance to exhaled airflow, making it easier to breathe.
• They are effective in about 80-90% of people with exercise-induced asthma.
• The effects last as long as 4-6 hours.
• They have no effect on the underlying cause of the asthma attack.
• They can also be used to relieve symptoms if an attack occurs.
• Side effects include rapid heartbeat and shakiness.
• Albuterol (Proventil, Ventolin) is the most frequently used beta2-agonist medication.

A longer-acting (12-hour) beta2-agonist inhaler is also available. This is more convenient for some people. For example, a child can use the long-acting inhaler before going to school in the morning to prevent an asthma attack during physical education class or recess.

For more information about other medications used to treat asthma, click here.

Next Steps Follow-up
Asthma is a long-term disease, but it can be managed. Your active involvement in treating this disease is vitally important.

• Take your prescribed medication(s) as directed.
• If you smoke, quit.
• See your health care provider regularly according to the recommended schedule.
• By following these steps, you can help minimize the frequency and severity of your asthma attacks.

Prevention
Treatment in exercise-induced asthma is focused on preventing or minimizing asthma attacks. If you take your prescribed medication as directed, you should be able to exercise without asthma symptoms.

Outlook
Most people with exercise-induced asthma are able to control their condition if they work together with a health care provider and follow their treatment regimen carefully.

People who do not seek medical care or do not follow an appropriate treatment plan are likely to experience worsening of their asthma and deterioration in their ability to function normally.

Support Groups and Counseling
Allergy & Asthma Network Mothers of Asthmatics
2751 Prosperity Avenue, Suite 150
Fairfax, VA 22031
(800) 878-4403

American Lung Association
61 Broadway, 6th Floor
New York, NY 10006
(212) 315-8700

Asthma and Allergy Foundation of America
1233 20th St NW, Suite 402
Washington, DC 20636
(202) 466-7643

For More Information Web Links

• Allergy & Asthma Network Mothers of Asthmatics
• American Academy of Allergy, Asthma & Immunology
• American College of Allergy, Asthma & Immunology
• American Lung Association
• Asthma and Allergy Foundation of America
• National Asthma Education and Prevention Program, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, Lung Diseases Information
• National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health