[Anaphylaxis induced by exertion]

Exercise induced anaphylaxis (EIA) is a relatively new syndrome described in 1980. It is associated with different kinds of exercise, although jogging is the most frequently reported. The clinical manifestations progress from pruritus, erythema and urticaria to some combination of cutaneous angioedema, gastrointestinal and laryngeal symptoms and signs of angioedema and vascular collapse. In the full-blown phase a differential diagnosis must be done with the following syndromes: exercise-induced asthma, idiopathic anaphylaxis, cardiac arrhythmias, carcinoid syndrome. An elevated serum histamine level during experimentally-induced attacks and cutaneous degranulation of mast cells after attacks proved a mast cell participation in the pathogenesis of the syndrome. As predisposing factors, a specific or even aspecific sensitivity to food has been reported and such cases are called "food-dependent EIA". Another precipitating factor includes drug intake; moreover a familial tendency has been reported in some studies. Although the prognosis of this syndrome is not well defined, a reduction of attacks occurs in 45% of patients by means of elimination diets and behavioural changes. Treatment of attacks should include all the manoeuvres efficacious in the management of conventional anaphylactic syndrome, including the epinephrine administration. Prevention of attacks may be achieved by limitation of the exercise program or interruption of the program at the appearance of the first premonitory symptoms. The use of H1 antihistamine-receptor antagonists in maintenance therapy seems to be useful, although no controlled data are available.