Anaphylaxis is an acute multi-system severe type I hypersensitivity allergic reaction. The term comes from the Greek words ἀνά ana, against, and φύλαξις phylaxis, protection. Due in part to the variety of definitions, between 1% and 15% of the population of the United States can be considered "at risk" for having an anaphylactic reaction if they are exposed to one or more allergens. Of those people who actually experience anaphylaxis, up to 1% may die as a result. Anaphylaxis results in approximately 1,500 deaths per year in the U.S. In the United Kingdom, mortality rates for anaphylaxis have been reported as up to 0...