What is anaphylaxis?
DefinitionAnaphylaxis is a life-threatening allergic reaction characterised by: 
- sudden onset
- rapid progression of signs and symptoms
- involving two or more organ systems
Incident RatesAlthough there is limited data on incident rates internationally, a review of 5843 epidemiological studies on behalf of the EAACI concluded that Anaphylaxis is a common problem, affecting an estimated 1 in 300 of the European population at some time in their lives.  The same European review highlighted 22% of emergency anaphylaxis cases involved children 
- HSE Anaphylaxis Guidelines, September 2016. Available via HSE Anaphylaxis guidelines, 2016
- Panesar SS, Javad S, de Silva D, et al. A on behalf of the EAACI Food Allergy and Anaphylaxis Group. The epidemiology of anaphylaxis in Europe: a systematic review. Allergy 2014; 68: 1353–1361. Available via Panesar S et al, The epidemiology of anaphylaxis in Europe, 2014