Anaphylaxis in the United States: an investigation into its epidemiology.

BACKGROUND Anaphylaxis is a severe, life-threatening allergic reaction that affects both children and adults in the United States. However, data regarding the incidence and prevalence of anaphylaxis and the number of deaths caused by it are limited. OBJECTIVE To provide a better understanding of the magnitude of the problem of anaphylaxis in the United States. METHODS A thorough review of the current medical literature was conducted to obtain prevalence estimates on each of the 4 major subtypes of anaphylaxis (food, drugs, latex, and insect stings). We calculated an overall estimate of the risk of anaphylaxis by using only estimates that are specifically derived from epidemiologic studies measuring anaphylaxis in the general population. RESULTS Known rates or cases of anaphylaxis were 0.0004% for food, 0.7% to 10% for penicillin, 0. 22% to 1% for radiocontrast media, and 0.5% to 5% after insect stings. There were 220 cases after latex exposure. Considering the 1999 US population of 272 million, the population at risk for anaphylaxis from food is 1099, from penicillin is 1.9 million to 27. 2 million, from radiocontrast media is 22 000 to 100 000, from latex is 220, and from insect stings is 1.36 million to 13.6 million. These calculations yield a total of 3.29 million to 40.9 million individuals at risk of anaphylaxis. CONCLUSION The occurrence of anaphylaxis in the US is not as rare as is generally believed. On the basis of our figures, the problem of anaphylaxis may, in fact, affect 1.21% to 15.04% of the US population.