Exercise-Induced Anaphylaxis (EIA)
Exercise-induced anaphylaxis (EIA) is a heterogeneous form of anaphylaxis in which exercise is the immediate trigger for the development of symptoms (Lieberman 2010). Clinical manifestation includes skin symptoms such as flushing, pruritus, urticaria, warmth, and extreme fatigue, which may progress to angioedema, and respiratory symptoms or collapse (Castells 2003). Symptoms usually begin to resolve as soon as the patient stops the activity. Symptoms are typically induced by aerobic forms of exercise, and rarely by weight training or isometric exercises. The level of exertion is typically moderate to high, but some patients (especially older adults) can have mild symptoms with light activity, such as walking (Perez-Rangel 2013).
Some patients only experience symptoms when other contributing factors are simultaneously present. These factors include ingestion of specific foods, as in food-dependent, exercise-induced anaphylaxis (FDEIA), non-steroidal anti-inflammatory drugs (NSAIDs), narcotics, heat and humidity, high pollen counts, premenstrual status, stress, infections, or sleep deprivation. Food-dependent EIA seems to be more common than pure EIA, based on the number of reported cases of each type in the literature. Common food triggers include grains such as wheat and shellfish, although many other foods have been implicated (Morito 2010, Du Toit 2007). In FDEIA both exercise and the food are separately tolerated.