What is Exercise-Induced Asthma (EIA)?
EIA is a condition of having coughing, wheezing, or chest tightness upon starting exercise. Twenty percent of the population has this happen. One fourth of these people also have regular asthma.
One tenth of every U.S. summer Olympic team has been found to have EIA. One fourth of the winter Olympic athletes have it (cold air is a strong trigger). Females may have more EIA than males.
What’s going on?
- The nose does three things to air: warms it, humidifies it, and filters it. When you start exercise, the body needs more oxygen and you switch from being a nose breather to being a mouth breather. Now the air hitting the lungs is colder, drier, and unfiltered. This air causes a temporary “hyperosmolarity” in the lungs and leads to a tightening of muscles surrounding the airways.
- Though the symptoms can start within 10 to 20 minutes of exercising, there is a 30 to 90 minute decrease in symptoms (“refractory period”) whereby the airway tightening relaxes somewhat.
- There can be variables that worsen EIA in certain individuals: breathing in pollens or molds (if the person is allergic); too much chlorine in pools; pesticides and fertilizers on playing fields; the taking of aspirin or NSAIDs (ibuprofen, Advil, Motrin) before exercise (these worsen certain individuals).
How is EIA diagnosed?
- To be practical, if it fits the picture of EIA and responds to albuterol, the diagnosis and the treatment is straightforward (if it walks like a duck, talks like a duck . . .).
Vocal cord dysfunction (or VCD, which is a spasm of the vocal cords) can look like exercise asthma.
- Unlike exercise asthma, the person has trouble getting air in (not out).
When there is a question, the old standard technique was to check FEV1 (“spirometry”, “lung functions”), then have the athlete run around for 10 minutes, then repeat the FEV1. If the FEV1 dropped by 10%, there was EIA. But this test is not very reproducible because of differences in humidity, temperature, and the time of day the test is done.
How is EIA treated? (Note: any or all of the methods below can be used)
1. Albuterol (or Xopenex) 2 puffs 10 to 60 minutes prior to exercise. Best to use a spacer with it.
2. Take a 12-hour bronchodilator in he morning (Foradil, Serevent, Advair, Symbicort).
3. Singulair in the morning unless the exercise is in the morning (takes 3 to 4 hours to work).
4. Low salt diet. Not yet a standard recommendation because athletes do need salt.
5. Warm up 15 to 30 minutes followed by 15 minute rest before the activity. This gets the peak of the exercise asthma out of the way and lets the refractory period kick in.
6. Fish oil supplements. One research study in 2006 showed benefit. Needs more research.
Kevin O’Brien, MD
Dr. O’Brien is a board-certified allergist with 25 years experience in the management of allergies, asthma, eczema, food allergies, sinusitis, and immune deficiencies. In the past he was medical director for the largest health education company in the United States and developed asthma programs for Kaiser Permanente, Anthem, Humana, and Prudential (the latter was the largest physician and patient education program ever developed in America). He also started the first patient education TV network in the United States (now in 27 cities). He sees both children and adults.