Exercise Induced Anaphylaxis (EIA) is a condition in which moderate to extreme exercise causes anaphylaxis in the patient (and in extreme cases even mild exercise cause symptoms). Many of these cases are further described as Food-Dependent Exercise Induced Anaphylaxis (FD-EIA), where a patient has eaten an allergen and then exercised, causing symptoms.
Exercise Induced Anaphylaxis (EIA)
Symptoms of EIA may start at any stage of exercise or just after it, but in most patients, they begin within 30 min after initiating exercise. The condition has been described in some studies occurring up to 4 hours later.
Food Dependent Exercise Induced Anaphylaxis (FD–EIA)
In comparison FD–EIA, ingestion of the causative food usually precedes exercise by several minutes or even hours. There are some cases where FD–EIA may also occur if the food is ingested soon after the completion of exercise. The triggering factor is important, so that the condition can be properly managed.
Animal allergy, dust mite allergy, pollens and certain drugs have also been known to be part of the trigger for this form of anaphylaxis.
Wheat Dependent Exercise Induced Anaphylaxis (WD-EIA)
This is a condition within FD-EIA which is well studied as it has been suggested in some studies that over 50% of FD-EIA cases are triggered by wheat allergens (see reference section).
Symptoms of EIA
- Extreme fatigue
- Warmth or Flushing
- Pruritus (severe itching) and Urticaria (hives)
- Angioedema (swelling of the body, hands, feet and/or face)
- Upper Respiratory Obstruction and Collapse
Why do symptoms only occur with exercise?
In many cases a weakly positive skin prick for the causative allergen is found. Patients can consume the allergen safely as long as they are not exercising or exercise without eating the allergen and remain safe, it is only the combination which causes anaphylaxis.
Hypothesis for why this happens include:
- Increased gastrointestinal permeability (where the cells of the intestines allow larger molecules, in this case allergens, to pass through to the gut)
- Blood flow redistribution (where blood is diverted away from other organs to the muscles used in exercise).
- Alterations in Blood Plasma
- Changes in Osmolarity and pH of the blood
For FD-EIA, diagnosis can start with skin prick tests (or blood tests) for possible allergens. The result may only be a mild positive.
WD-EIA can be diagnosed the same way, but with IgE for omega-5-gliadin (the major wheat allergen) specifically tested for.
Management of EIA
Antihistamines should never be used as an alternative to epipens for those suffering from anaphylaxis. It is recommended in the UK that in these cases that two epipens are prescribed in case of unit failure or a biphasic reaction.
Avoidance of exercise after your trigger allergen is consumed or avoidance of your trigger allergens if you intend to exercise. Management of the condition varies from case to case depending on the severity, but should be discussed with your healthcare provider.
A higher chance of EIA has been linked to:
- A warm environment
- Cold environment
- High humidity
- Aspirin intake
- Menstrual cycle
Knowing which allergens bring the condition on, plus any of the additional factors as above, can all help managing the condition.
Exercise Induced Anaphylaxis should not be confused with cholinergic urticaria, which is chronic hives, which starts with an elevated body temperature.
**I usually use free photos from morguefile for my blog, but this is my football loving daughter practising her kangaroo**