Anaphylaxis is a life-threatening allergic reaction that happens very quickly. It can be caused by food, medicine or insect stings. Call 999 if you think you or someone else is having an anaphylactic reaction.

Symptoms of anaphylaxis happen very quickly.

They usually start within minutes of coming into contact with something you're allergic to, such as a food, medicine or insect sting.

Symptoms include:

• swelling of your throat and tongue
• difficulty breathing or breathing very fast
• difficulty swallowing, tightness in your throat or a hoarse voice
• wheezing, coughing or noisy breathing
• feeling tired or confused
• feeling faint, dizzy or fainting
• skin that feels cold to the touch
• blue, grey or pale skin, lips or tongue – if you have brown or black skin, this may be easier to see on the palms of your hands or soles of your feet

You may also have a rash that's swollen, raised or itchy.

Call 999 if:

Follow these steps if you think you or someone you're with is having an anaphylactic reaction:

1. Use an adrenaline auto-injector (such as an EpiPen) if you have one – instructions are included on the side of the injector.
2. Call 999 for an ambulance and say that you think you're having an anaphylactic reaction.
3. Lie down – you can raise your legs, and if you're struggling to breathe, raise your shoulders or sit up slowly (if you're pregnant, lie on your left side).
4. If you have been stung by an insect, try to remove the sting if it's still in the skin.
5. If your symptoms have not improved after 5 minutes, use a 2nd adrenaline auto-injector.

Do not stand or walk at any time, even if you feel better.

How to use an adrenaline auto-injector

There are different types of adrenaline auto-injectors and each one is given differently.

• EpiPen instructions (EpiPen website)
• Jext instructions (Jext website)

Anaphylaxis needs to be treated in hospital immediately.

Treatments can include:

• adrenaline given by an injection or drip in your vein
• oxygen
• fluids given by a drip in your vein

You'll usually stay in hospital for around 2 to 12 hours, but you may need to stay longer.

Before you leave hospital, you'll be given 2 adrenaline auto-injectors to keep in case you have another anaphylactic reaction.

An adrenaline auto-injector is a special device for injecting adrenaline yourself. You'll be told how and when to use it.

You should be shown how to use your adrenaline auto-injector each time you're prescribed it.

You may also be referred to an allergy specialist for tests and advice.

There are some things you can do to help prevent anaphylaxis or prepare for if it happens.

More information

There's more advice about what you can do to avoid common allergies. Find out more about:

• food allergy
• insect bites and stings
• medicine allergy (Allergy UK website)
• latex allergy (Allergy UK website)

Anaphylaxis happens when your body has a serious reaction to something you're allergic to.

Allergies that can sometimes cause anaphylaxis include:

• foods such as nuts, cows' milk, eggs, fish or sesame seeds
• medicines such as antibiotics or non-steroidal anti-inflammatory drugs (NSAIDs)
• insect stings, such as wasp and bee stings
• anaesthetics
• latex (a type of rubber found in some rubber gloves and condoms)

Sometimes it's not known what caused an anaphylactic reaction.