What is anaphylaxis?

Information on anaphylaxis

Anaphylaxis, also known as anaphylactic shock, is a severe and potentially fatal allergic reaction. The whole body is affected, it may start suddenly, within seconds or minutes, or take a few hours to develop.

When a person encounters an allergen for the first time the immune system becomes sensitised to the allergen. The next time a person meets this allergen the immune system will remember and an allergic reaction may be much faster or more severe than the previous reaction.

Anaphylaxis is the most serious type of allergic reaction. But it nearly always starts with one or more  symptoms. You may recover from these minor early symptoms and never experience them again or you may have repeated allergic reactions.  Sometimes, however, these symptoms can develop into an anaphylactic shock - fainting or collapse, which is caused by a rapid fall in blood pressure, and severe breathing difficulties.

Most people are not allergic to insect stings but everyone should be able to recognise the difference between an allergic reaction and a normal localised reaction. The most serious reaction to an insect sting is an allergic one which may lead to anaphylaxis.

Adrenaline is the first line treatment for anaphylaxis and each patient identified to be "at risk" from anaphylaxis should carry two auto-injectors at all times.

As adrenaline does not treat the underlying allergy, it is not a cure. It is vital that patients are referred to a physician with specialist knowledge of allergies for an evaluation in order to establish the correct diagnosis and the need for further treatment.

Last updated: 2017.12.06