Anaphylaxis. A preventable emergency.

Anaphylaxis is a life-threatening reaction that may be caused by a variety of agents. Diagnosis depends on the presence of a constellation of symptoms (eg, laryngeal edema, bronchospasm, hypotension, urticaria). The goal of therapy is maintenance of an effective airway, respiratory function, and circulation. Subcutaneous epinephrine, H1 and H2 antihistamines, and a prolonged period of observation (at least 8 hours) should be used in all patients. After the acute attack has been managed, a thorough investigation of possible causes should be made and the patient referred to a specialist, if indicated. Desensitization therapy, premedication before high-risk exposures, and careful avoidance of known causative agents are effective preventive measures. Direction in self-administration of epinephrine is critical in these patients and may prove lifesaving.