A case report in 1979 on EIA was the first research of its kind, where a patient was described to experience anaphylactic shock related to exercise 5–24 hours following the consumption of shellfish.
[4] The condition is thought to be more prevalent in women, with two studies of EIA patients reporting a ratio of 2:1 for females:males with the disorder.
[9] More severe symptoms might include the swelling of the tongue, difficulty in swallowing or breathing, constriction of the airways, feeling faint, and unconsciousness.
[6] A paper by Sheffer and Austen (1980) splits an EIA event into four distinct stages: prodromal, early, fully developed, and late.
[6] Food-dependent exercise-induced anaphylaxis (FDEIA) is a subcategory of the disorder where exercise only invokes a reaction when followed by the ingestion of a food allergen.
[12][13] Other common foods thought to be linked to FDEIA include shellfish, seeds, dairy (in particular cow's milk), fruits and vegetables (such as grapes, onions and oranges), meats, and even mushrooms.
These include the consumption of alcohol, exposure to pollen, extreme temperatures, the taking of non-steroidal anti-inflammatory drugs (NSAIDs), and even certain phases of the menstrual cycle.
[7] Omega-5-gliadins, a compound found in wheat that is commonly associated with FDEIA, is cross-linked by transglutaminase, resulting in large formations of peptide aggregates, and leads to an increase in IgE binding.
[7] It has been suggested that food-sensitised immune cells associated with the gut do not evoke anaphylactic symptoms so long as they remain in a local circulation.
[25] The theory suggests that if these sensitised cells are shifted to the skin and/or skeletal muscles following exercise, FDEIA symptoms are likely to occur.
[25] A 2010 study demonstrated that food allergens were well tolerated by mast cells in the intestinal tract, and thus no symptoms occurred at rest.