How is anaphylaxis recognized?

Abstract

Prompt recognition of anaphylaxis may be lifesaving. Although its presentation has been described, there are no criteria for making a rapid diagnosis. A systematic review of the literature was performed to develop objective clinical criteria aimed at improving the recognition of anaphylaxis. A MEDLINE search of the word anaphylaxis over a 1-year period identified all of the reports describing the initial manifestations. Of 160 reviewed articles, 116 contained a clinical description of anaphylaxis. Eighty-nine (77%) of these 116 articles were case reports. Hypotension (84 reports [72%]) and urticaria and/or angioedema (70 reports [60%]) were the most frequently described signs. Of the identified allergens, 73% were diagnostic or therapeutic agents. In 72 of the 80 articles in which a reaction time could be identified, the reaction occurred within 60 minutes. As a result of this analysis, we conclude that anaphylaxis recognition may be improved by the identification of one of the following criteria, which describe the presentation in 82% of the analyzed reports: (1) exposure to an allergen within 1 hour produces one or more systemic signs (hypotension, upper or lower respiratory tract compromise, or increased gastrointestinal tract motility), or (2) urticaria or angioedema accompanies at least one of these systemic signs.