[Immediate drug hypersensitivity. Epidemiology, clinical features, triggers and management].

Drug hypersensitivity reactions affect more than seven percent of the population and are a concern for patients and doctors alike. In a substantial part of such reactions, IgE-mediated mechanisms have been documented. Clinical manifestations of immediate reactions, which occur directly after drug intake (mostly ≤ 1 h), are acute urticaria, angioedema, dyspnea and other symptoms of anaphylaxis in the skin, gastrointestinal tract, respiratory tract or cardiovascular system. Although normally leading to milder reactions, drugs are also the most frequent elicitors of fatal anaphylaxis. The median time interval between systemic drug application and clinical death is 5 min. The most common elicitors of immediate reactions are analgesics, antibiotics, radiocontrast media and muscle relaxants. The aim of history and experience guided skin tests ± laboratory tests is to document a sensitization, which depends on the eliciting drug and is only successful in less than half of the patients. Else a drug provocation test under controlled conditions is necessary to clarify the diagnosis and to confirm or exclude a drug hypersensitivity reaction. Therapy consists in drug avoidance or in pressing indications in tolerance induction by a "drug desensitization".