Anaphylaxis is a severe life-threatening allergy. Normally, the immune system defends the body against threats such as bacteria and viruses. An allergy is when a person’s immune system reacts abnormally to something it’s exposed to- for example, food, pollen, animal dander, insect bites or medication. The immune system releases chemicals in response to the trigger. Mild allergy leads to symptoms such as itchy eyes, hives and a runny nose. However, in anaphylaxis the allergic reaction is much more severe and can happen within moments of exposure to a trigger- a wave of chemicals is released by the immune system, quickly affecting a person’s breathing and circulation. It is a medical emergency and usually requires urgent treatment with an adrenaline injection (such as an Epipen).