Learn about anaphylaxis, test your knowledge & discover posters and printouts
What is Anaphylaxis?
Anaphylaxis is a severe, often sudden and potentially life-threatening allergic reaction. It occurs when an individual with an allergy (even known to them or not) is exposed to a trigger. This trigger is known as the allergen. An allergy is different to an intolerance and is much more serious.
Anaphylaxis can be life-threatening and always required immediate emergency attention.
Individuals who have been diagnosed with an anaphylactic allergy may carry an adrenaline auto-injector. This is a medical device used for the treatment of acute allergic reactions.
Symptoms of anaphylaxis
Anaphylaxis usually develops suddenly and worsens quickly.
Symptoms include:
feeling lightheaded or faint
breathing difficulties – such as fast, shallow breathing
wheezing
a fast heartbeat
clammy skin
confusion and anxiety
collapsing or losing consciousness
There may also be other allergy symptoms, including an itchy, raised rash (hives); feeling or being sick; swelling or stomach pain.
What to do if someone has anaphylaxis
Anaphylaxis is a medical emergency. It can be very serious if not treated quickly.
If someone has symptoms of anaphylaxis, you should:
Use an adrenaline auto-injector if the person has one – but make sure you know how to use it correctly first. You can watch our video here.
Call your emergency services (999 in the UK, 911 in the USA) for an ambulance immediately (even if they start to feel better) – mention that you think the person has anaphylaxis, this will ensure your emergency is pushed to a priority case.
Remove any triggers if possible – for example, carefully remove any nuts in the surrounding area or any stinger stuck in the skin.
Lie the person down flat – unless they're unconscious, pregnant or having breathing difficulties.
Give another injection after 5 to 15 minutes if the symptoms do not improve and a second auto-injector is available.
