ABSTRACT
I. INTRODUCTION Anaphylaxis is not a reportable disease, and both its morbidity and its mortality are probably underestimated. A variety of statistics on the epidemiology of anaphylaxis have been published (1-10) (Table 1). There is no universally accepted clinical definition of anaphylaxis (11,12). In this discussion, anaphylaxis is defined as an acute life-threatening reaction, usually, but not always, mediated by an immunological mechanism (anaphylactoid reactions are thought to be IgE independent), that results from the sudden systemic release of mediators from mast cells and basophils. It has varied clinical presentations that consist of some or all of the following signs and symptoms: pruritus, flushing, urticaria and/or angioedema, bronchospasm, dysphonia, laryngeal edema, hyperperistalsis, hypotension, and/or cardiac arrhythmias. Other symptoms can occur, such as dysphagia, nausea, vomiting, rhinitis, lightheadedness, headache, feeling of impending doom, and unconsciousness.
