Condition: Exercise-induced asthma (EIA) or exercise-induced bronchoconstriction (EIB) is a lung condition. Airway narrowing, or bronchoconstriction, occurs during or after exercise, leading to asthma-like symptoms, even if a person does not have asthma. Specifically, EIA is used to refer to individuals with a history of asthma for whom exercise is a trigger for asthma symptoms. Similarly, EIB refers to individuals without asthma history who experience airway narrowing during or after exercise.
Background: Experts believe EIA is caused by a state of chronic airway inflammation promoted by an abundance of inflammatory agents like histamines and leukotrienes that directly narrow the airways during or after exercise. Similarly, EIB is linked to environmental and individual risk factors (e.g. personal or family history of allergic rhinitis) that result in airway narrowing with exercise. The rate of EIA varies, depending upon the sport involved and the intensity of the exertion.
Risk Factors: Risk factors include exercising during colder seasons and in dry weather. Other risk factors include exposure to allergens, having a personal or family history of asthma, hay-fever or nasal inflammation, and living in an urban area. A significant number of individuals with asthma [40-90%] of will experience EIA. Individuals exercising near chemicals like chlorine from swimming pools or insecticides and fertilizers used to maintain fields are at greater risk for EIA/EIB. EIA and EIB may be seen at any age and do not appear to be more common in either gender.
History and Symptoms: Individuals experiencing EIA/EIB will report coughing, wheezing, shortness of breath, excessive mucous production, and/or chest tightness associated with exercise. These symptoms typically improve once the activity is stopped, however, symptoms occurring 4-8 hours after exercise (late response) have been reported. Some individuals also experience fatigue, headache, dizziness or abdominal pain.
Physical Exam: The exam is comprehensive, and the physician typically checks a patient’s head, eyes, ears, nose, throat, chest, heart, lungs, limbs and skin.
Diagnostic Process: Although often treated based on symptoms and response to medications alone, a physical medicine and rehabilitation (PM&R) physician, also known as a physiatrist, who specializes in cardiopulmonary rehabilitation and/or sports medicine is best trained to perform precise functional assessments of an individual at the time of diagnosis and to monitor progress. The PM&R physician may arrange to assess the patient during sport specific activities or can have the individual run on a treadmill or use other exercise equipment to cause the person’s breathing rate to rise. This allows the physician to better assess the condition. Furthermore, athletes participating in competitions with strict substance policies would benefit from the expertise of a sports trained PM&R physician knowledgeable of WADA (World Anti-Doping Agency) policies for EIA/EIB testing.
Rehab Management: EIA is best managed as a broader treatment plan to lower chronic inflammation in the airways. EIB management can focus on avoiding or modifying environmental triggers to prevent future attacks. When indicated, some individuals can take medications prior to exercising that help open up the airways to prevent airway narrowing associated with exercise.
Other Resources for Patients and Families: People with asthma can learn more at the Asthma and Allergy Foundation of America.