EXERCISE-INDUCED ASTHMA
DEFINITION:
Cough, wheeze, and/or dyspnea during or after exercise.
EPIDEMIOLOGY:
- incidence: 15% of the population
- age of onset:
- risk factors:
- family history of atopy
- past medical history of atopy
- 85-90% of those with allergic asthma
- 30-40% of those with allergic rhinitis
PATHOGENESIS:
- any factor which prevents warming and humidificatin of the
air before it is exposed to the airway -> alters the temperature
of the airway -> release of inflammatory mediators ->
bronchoconstriction -> exercise-induced asthma (EIA)
- an alternative hypothesis states that it is not an altered
temperature which triggers the bronchoconstriction but an
elevated evaporative loss of water in the airways leading to
hyperosmolality of the mucosa of the airways -> release of
inflammatory mediators -> bronchoconstriction
CLINICAL FEATURES:
- onset
- when did the problems begin
- precipitation
- which exercises or activities trigger the asthma
- palliation
- management stratagies thus far and results
- quality
- cough, wheezes, and/or dyspnea
- radiation
- evidence of other asthma triggers, i.e., viral, allergens
- severity
- do symptoms interfere with or stop participation in the
activity (i.e., removed from the activity)
- what stops activity (legs vs lungs)
- can patient keep up with teammates
- patient missing shifts, games
- timing
- getting better or worse
- summer vs winter
- associated symptoms
- chest tightness, palpatations, rapid heart rate
- cough at night; cough with phelgm
2. Respiratory Manifestations
- cough, wheeze, and/or dyspnea during or following exercise
- aggrevating factors which make EIA more likely
- air pollutants (i.e., sulfer dioxide)
- cold air or low humidity
- high pollen count
- nasal blockage (mouth breathing)
- viral upper respiratory tract infections (UTI)
- associated symptoms
- chest tightening and tachycardia may occur 5-10 minutes
after the end of exercise
INVESTIGATIONS:
- measured before, during, and 20 minutes after the exercise
- may be altered hours after the end of exercise
- evidence of an obstruction pattern in response to exercise:
- decreased FEV1
- decreased FEV1/FVC
MANAGEMENT:
- to allow the patient to participate fully in any activity
they choose
- normal exercise tolerance
- normal spirometry and peak flows
- infrequent or no bronchodilator use
3. Activity Modification
- tend to avoid strenuous cold weather aerobic sports
(running, cross country skiing, skating)
- restrict or avoid exercising with high pollution or pollen
levels, low temperature, or if sick with a viral UTI - swimming
often considered to be the sport of choice for many asthmatics
due to a warm, humid environment, horizontal posi-tioning, year
round activity, and use of upper body muscles
- - anaerobic exercises are also good
- warm-up exercises
- may produce a refractory period where the degree of
bronch-contriction is less
- best to perform a long period of submaximal warm-up
exer-cise
4. Medications
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