Exercise-induced anaphylaxis (EIA) is a rare disorder in which anaphylaxis occurs after physical activity. [1] The symptoms may include pruritus, hives, flushing, wheezing, and GI involvement, including nausea, abdominal cramping, and diarrhea. If physical activity continues, patients may progress to more severe symptoms, including angioedema, laryngeal edema, hypotension, and, ultimately, cardiovascular collapse. Cessation of physical activity usually results in immediate improvement of symptoms. (See Clinical Presentation.)

Sheffer and Austen described 4 phases in the sequence of the anaphylaxis attack—prodromal, early, fully established, and late—in a case series of 16 patients aged 12-54 years with exercise-induced anaphylaxis. [2] Prodromal symptoms included a feeling of fatigue, generalized warmth and pruritus, and cutaneous erythema. The early phase featured generalized urticaria. In fully established attacks, symptoms included choking, respiratory stridor, GI colic, nausea, and vomiting. Late sequelae included frontal headaches that persisted for 24-72 hours. (See Clinical Presentation.)

Vigorous forms of physical activity such as jogging, tennis, dancing, and bicycling are more commonly associated with exercise-induced anaphylaxis, although lower levels of exertion (eg, walking and yard work) are also capable of triggering attacks. In a long-term follow-up study, the physical activity most often associated with exercise-induced anaphylaxis was jogging. [3] Other reports have implicated running, soccer, raking leaves, shoveling snow, and horseback riding. [4] (See Etiology.)

Exercise-induced anaphylaxis attacks are not consistently elicited by the same type and intensity of physical activity in a given patient. Co-factors such as foods, alcohol, temperature, drugs (eg, aspirin and other nonsteroidal anti-inflammatory drugs), humidity, seasonal changes, and hormonal changes are important in the precipitation of attacks. [1] (See Etiology.)

A distinct subset of exercise-induced anaphylaxis is food-dependent exercise-induced anaphylaxis (FDEIA), in which anaphylaxis develops only if physical activity occurs within a few hours after eating a specific food. Neither food intake nor physical activity by itself produces anaphylaxis. [5]

The foods most commonly implicated in food-dependent exercise-induced anaphylaxis are wheat, shellfish, tomatoes, peanuts, and corn. [6] However, the disorder has been reported with a wide variety of foods, including fruits, seeds, milk, soybean, lettuce, peas, beans, rice, and various meats.

One case report described a patient who developed symptoms of anaphylaxis only after simultaneous ingestion of 2 foods (wheat and umeboshi) prior to exercise. [7] In the nonspecific form of food-dependent exercise-induced anaphylaxis, eating any food prior to exercise induces anaphylaxis. [8]

Inhalant allergens have also been implicated in exercise-induced anaphylaxis. In a case report, a 14-year-old boy presented with severe exercise-induced anaphylaxis after the ingestion of Penicillium mold–contaminated food and running in the school. [9] In another case report, a 16-year-old girl presented with exercise-induced anaphylaxis after ingestion of wheat flour contaminated with storage mites. [10]

Familial exercise-induced anaphylaxis has been described in patients with a family history of exercise-induced anaphylaxis and atopy. [11] Seven males from 3 generations were described with cutaneous and respiratory symptoms induced by physical activity. [12]

Prevention remains the best treatment for patients with exercise-induced anaphylaxis (see Treatment and Management). Reducing physical activity to a lower level may diminish the frequency of attacks. In patients whose attacks are associated with ingestion of food, avoiding the offending food for 12 hours prior to exercise is essential. If no offending food is known, then the patient should avoid eating any food 6-8 hours prior to exercise. Patients should avoid exercise in extremely humid, hot, or cold weather and during the allergy season.

Patients should be instructed on the proper use of emergency injectable epinephrine (Adrenaclick, EpiPen, Twinject) and have one available at all times. Patients should wear a medical alert bracelet with instructions on the use of epinephrine. (See Medication.)

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