exposure to an allergen. Theories for the pathophysiology of EIA include increased gastrointestinal permeability, increased tissue enzyme activity, and blood flow redistribution. Gastrointestinal permeability Exercise is known to increase absorption from the gastrointestinal tract. It is theorised that increased or altered gastrointestinal permeability enhances contact of allergens with the gut-associated immune system. In some FDEIA patients, the appearance and/or severity of symptoms depends on the amount of the patient's trigger food ingested. An increase in gut permeability may also increase the risk of absorption of 'partially digested allergenic proteins'. Supporting research for this theory includes a study by Matsuo et al. (2005), where wheat-dependent EIA sufferers were found to have omega-5-gliadins in their sera following exercise and consumption of wheat, but not in patients that ingested wheat only. Increased tissue enzymatic activity Another theory is that exercise and aspirin could activate tissue transglutaminase in intestinal mucus. 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. Blood flow redistribution During exercise, blood is redistributed from inactive to active tissues in the body. 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. 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. A 2010 study demonstrated that food allergens were well tolerated by mast cells in the intestinal tract, and thus no symptoms occurred at rest. Mast cells are structurally different in the gut than those found in the skin or skeletal muscles, and thus could be induced by food allergens. Treatment If exercise is stopped when symptoms are first detected, improvement in condition normally occurs within minutes, and no further treatment is required. Common treatments for the condition include taking regular anti-histamines, the use of an epinephrine injector (commonly known as an EpiPen), and through abstinence of exercise. In a 1999 study, 56% of sufferers reported the use of anti-histamines as treatment for their EIA, and 31% reported having treated the condition with epinephrine. Many patients reported treating the condition with changes in behaviour, with 44% of EIA sufferers reporting having reduced the incidence of attacks by avoiding exercise during "extremely hot or cold weather", 37% by avoiding