[Exertion-induced anaphylaxis].

The syndrome of exercise induced anaphylaxis represents a distinct form of physical allergy. This syndrome and the features which distinguish it from other forms of physical allergy are discussed in the context of 10 case reports. The symptoms usually start after 5-30 minutes' exercise with cutaneous pruritus, warmth and progress to urticaria and angioedema. In 3 cases signs of laryngeal edema were present; additional manifestations included upper respiratory distress, gastrointestinal tract symptoms and collapse. The syndrome is distinct from exercise induced asthma or cholinergic urticaria. One patient had both cholinergic urticaria induced by stress, heat and exercise, and anaphylactoid symptoms induced by exercise alone. While the symptoms of cholinergic urticaria subsided after 2-4 hours, the anaphylactoid symptoms lasted up to 48 hours. The symptoms are elicited irregularly, which suggests a multifactorial trigger mechanism. The intake of particular foods or acetylsalicylic acid, and certain weather conditions, are possible cofactors. In 8 of 10 patients an atopic diathesis was found but no exposition to a specific allergen, which could explain the symptoms, was observed. Therapy consists of avoidance of cofactors, change of training habits and cessation of exercise as soon as prodromal symptoms develop. If attacks are frequent, antihistamines or ketotifen can be tried. The acute attack should, like other anaphylactoid reactions, be treated by antihistamines, injection of epinephrine (s.c.) and infusions (colloidal solutions).