What is Exercise-Induced Anaphylaxis?

exercise-induced allergic reaction
Are you allergic to exercise?. Sam Edwards/Caia Images/Getty Images

Have you ever had an allergic reaction that occurred after exercising?  Have you experienced symptoms such as swelling and hives occurring out of the blue when you were gardening? Or have you been surprised by a sudden onset of asthma-like symptoms when walking or running (and you don’t have asthma)?

You may have what experts call exercise-induced anaphylaxis.


An exercise-induced allergic reaction is a rare condition, generally classified into 2 categories: exercise-induced anaphylaxis (EIA) and food-dependent, exercise-induced anaphylaxis (FDEIA).

EIA is reported to occur in 5 to 15% of all anaphylactic cases. The prevalence of food-dependent EIA is not well documented, but it is estimated to be about one third to one half of all EIA patients.

In EIA, exercise precipitates a reaction. In FDEIA, food ingestion before, in combination with, or after exercise is believed to cause the reaction.

Both EIA and food-dependent EIA reactions are rare and one may not even recognize what is happening. They may be life threatening and triggered by physical activity, including something as mild as walking to a more intense exercise like running. Reactions have been documented for the following activities: walking, jogging, aerobics, tennis, biking, dancing and racquetball.

EIA and FDEIA may not be predictable or repeatable. In other words, the reaction you had when gardening or running may occur once and not occur again. on the other hand, in some individuals, a repeat scenario is possible.

External factors in addition to exercise may play a role in triggering a reaction such as high humidity, or a warm or cold environment.

The “why” of EIA and FDEIA is not fully understood, although several explanations are presented, including increased blood flow to the stomach and intestines, redistribution of blood flow throughout the body when exercising, and increased osmolality which may trigger histamine release and the onset of allergic symptoms.

While the mechanism isn’t fully understood, experts believe that exercise increases the permeability of the gut, allowing an increased amount of allergens to present themselves to the immune system and trigger a reaction.


Symptoms of an allergic reaction may occur at any time during exercise but about 90% of patients report symptoms occurring within 30 minutes of starting exercise, on average. The most frequently reported symptoms are: itchy skin, hives, swelling, flushing, shortness of breath, loss of consciousness, sweating, headache, nausea and vomiting. Although EIA and FDEIA are considered life-threatening conditions, fatalities are rare.

In patients with food-dependent EIA, the ingestion of a food prior to exercise or even after exercise can set off symptoms. Seafood, celery, wheat and cheese are common food culprits associated with FDEIA. Other notable foods are cereal grains, seafood, nuts, fruits, vegetables, dairy, and alcohol. Individuals may be able to eat these foods without symptoms provided they don’t exercise.

Medications may also trigger EIA or FDEIA reaction during exercise. They include aspirin, ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs). It is possible that any medication may trigger EIA when taken before exercising.


Three types of exercise-induced allergic reaction exist:

Cholinergic urticaria (hives)

This allergic reaction is characterized by small pimple-like bumps that are surrounded by a reddish halo. These spots usually start on the upper chest and neck but may spread to the entire body. The lesions themselves may resolve within 15-20 minutes, however, large amounts of hives may take several hours to resolve. These lesions are known to occur due to exercise, warmth and emotional stress.

Classic exercise-induced anaphylaxis

This condition is characterized by hives or swelling with upper respiratory obstruction and low blood pressure caused by exercise. Symptoms may include itching, a sensation of choking, nausea, headache and wheezing. Jogging and running have been reported to induce this condition, but other activities include dancing, volleyball, skiing and even yard work. Symptoms typically last 30 minutes to four hours after stopping exercise. An individual can have one single reaction or more than one annually. The incidents are not consistently reproducible and thus are unpredictable.

Variant exercise-induced anaphylaxis

This is the least common form of exercise-induced allergic reaction. Like the cholinergic urticaria, this condition produces small bumps and is associated with increased levels of histamine. What is different is that this condition is only stimulated by exercise and may progress to anaphylaxis. This is reportedly responsible for about 10% of all cases of exercise-induced anaphylaxis.

If you think you've had a reaction during exercise, consult your healthcare professional immediately.


Exercise-induced anaphylaxis and urticaria. American Assocation of Family Physicians. http://www.aafp.org/afp/2001/1015/p1367.html

Barg et al. Exercise-induced Anaphylaxis: An update on Diagnosis and Treatment. Curr Allergy Asthma Rep. 2011; 11(1) 45-51. 

Exercise-induced anaphylaxis. http://emedicine.medscape.com/article/886641-overview 

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