Anaphylaxis is an acute multisystem severe type I hypersensitivity reaction. The term comes from the Greek words ἀνά ana (against) and φύλαξις phylaxis (protection). See Wikipedia.

Some things are known about the predisposing and risk factors for anaphylaxis.

Anaphylaxis is the most severe manifestation of a mast cell-dependent reaction. It is a rare disease and most recent data indicates a continuous increase of affected individuals. Limitations regarding the incidence of anaphylaxis are the lack of a unique definition and the fact that patients are often seen by different medical specialties (e.g. emergency doctors, allergists or other clinicians). However, based on the published data it can be summarized that the most frequent causes of anaphylaxis are food, venom and drugs, and their frequency as an elicitator depend on age. Risk factors for anaphylaxis include age, the presence of other allergic or cardiovascular comorbidities – and gender. More data throughout different countries are needed to monitor the elicitating factors and identify patients at risk1.

  • Several studies in the United States assessed the incidence of anaphylaxis related to food. These studies found wide differences in the rates (from 1/100,000 population to as high as 70/100,000 population) of hospitalization or emergency department visits for anaphylaxis, as assessed by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes or medical record review.
  • The proportion of anaphylaxis cases thought to be due to foods also varied between 13 and 65 percent, with the lowest percentages found in studies that used more stringent diagnostic criteria for anaphylaxis.

Page last edited: 08 May 2011


  1. Worm M. Epidemiology of anaphylaxis. Chem Immunol Allergy. 2010; 9512-21.