Exercise-induced anaphylaxis

Exercise-Induced Anaphylaxis (EIAn) is a rare condition in which anaphylaxis, a serious or life-threatening allergic response, is brought on by physical activity. Approximately 5-15% of all reported cases of anaphylaxis are thought to be exercise-induced. Exercise-Induced Anaphylaxis (EIAn) is a rare condition in which anaphylaxis, a serious or life-threatening allergic response, is brought on by physical activity. Approximately 5-15% of all reported cases of anaphylaxis are thought to be exercise-induced. The exact proportion of the population with EIAn is unknown, but a 2001 study of 76,229 Japanese junior high students showed that the frequency of EIAn was 0.031%. EIAn is not a widely known or understood condition, with the first research on the disorder only having been conducted in the past 40 years. A case report in 1979 on EIAn 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. The condition is thought to be more prevalent in women, with two studies of EIAn patients reporting a ratio of 2:1 for females:males with the disorder. There is, however, thought to be no link to race. Survey results from EIAn patients have shown that the average number of attacks per year is 14.5. However, most sufferers of EIAn report that both severity and frequency of attacks decrease over time. The anaphylaxis campaign splits symptoms of EIAn into two categories: mild and severe. Mild symptoms may include 'widespread flushing of the skin', hives or urticaria, swelling of the body (angioedema), swelling of the lips, and nausea or vomiting. More severe symptoms might include the swelling of the tongue, difficulty in swallowing or breathing, constriction of the airways, feeling faint, and unconsciousness. Symptoms can start immediately following exercise, but 90% of patients report experiencing an attack 30 minutes following activity. A paper by Sheffer and Austen (1980) splits an EIAn event into four distinct stages: prodromal, early, fully developed, and late. Characteristic symptoms of the prodromal stage include redness and itching. In the early stage, generalised urticaria develops. If the reaction does not diminish, it may become fully developed EIAn, in which gastrointestinal symptoms and constriction of the airway may occur. The late phase, which follows recovery from the reaction, includes frontal headaches and a feeling of fatigue; these symptoms may manifest themselves up to 72 hours following onset of the reaction. Cardiovascular symptoms are reported in 1/3 of patients diagnosed with EIAn.