Recognizing and Diagnosing Anaphylaxis

Anaphylaxis can be recognized by the presence of symptoms such as itching, flushing, hives, angioedema, or gastrointestinal symptoms. The onset of symptoms usually occurs within minutes to a few hours after exposure to an allergen. The diagnosis of anaphylaxis is supported by the presence of two or more organ systems being affected, as well as a likely exposure to an allergen. Tryptase levels in the blood can also be helpful in confirming the diagnosis, with levels above 11 micrograms per liter being supportive of anaphylaxis. Not all cases of anaphylaxis will have elevated tryptase levels, so clinical judgement is crucial.