Emergency advice

If someone’s having an allergic reaction:

  1. Call 999/112 straight away.
  2. Use their auto-injector if they have one.
  3. Monitor their breathing.

What is an allergy?

An allergy is an abnormal reaction to an allergen or ‘trigger’ substance.

One of the most common allergens is plant pollen, which often causes hay fever. Other allergens include animal hair, bee stings, medication (especially penicillin), and food, such as nuts and shellfish.

What is a severe allergic reaction?

A severe allergic reaction can develop just seconds after someone comes into contact with the allergen. It can affect the whole body, and if it’s not treated quickly enough it could be fatal. This is called anaphylactic shock.

Signs and symptoms

Look for: 

  • a red, itchy rash, or raised area of skin (weals)
  • red, itchy, watery eyes
  • swelling of hands, feet, or face
  • abdominal pain, vomiting, or diarrhoea.

There may also be:

  • difficulty in breathing
  • swelling of tongue and throat with puffiness around eyes
  • confusion and agitation
  • signs of shock leading to collapse and unresponsiveness.

What to do

  1. Call 999 or 112 straight away and tell ambulance control that you suspect a severe allergic reaction.

  2. If someone’s having a severe allergic reaction, then they may have medication, like an auto-injector. This is a pre-filled injection device containing adrenaline which when injected, can help reduce the body’s allergic reaction. 

    • Check if they have one, and if they do, help them to use it or do it yourself following the instructions.
  3. Help them to get comfortable and monitor their breathing and level of response.

    • Repeated doses of adrenaline can be given at five-minute intervals if there is no improvement or the symptoms return.

Related first aid advice

How to do the primary survey

Use the primary survey to quickly assess the situation and check the casualty for injuries or conditions that could be immediately life threatening. Find out what to do.

How to do CPR on an adult

If an adult is unresponsive and not breathing normally, you need to call 999 or 112 for emergency help and start CPR straight away. Learn what to do.

Insect stings

Insect stings can be painful but are not usually dangerous. However, stings to the mouth or throat can be more serious. Find out what to do.

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