Severe allergic reaction or anaphylactic shock in babies
An allergy is the body’s unexpected reaction to something it has
come into contact with. Your baby may be allergic to cow’s milk,
plant pollen, animal hair, insect stings or specific drugs. As you
wean your baby you may find they are allergic to specific foods,
such as fruit, shellfish and nuts.
A severe allergic reaction can develop within just a few
seconds. It can be very frightening if your baby has an allergic
reaction and it can be life-threatening if not treated quickly.
Watch our video - what to do if your baby has a severe allergic
reaction
What to look for – severe allergic reaction in babies
These are the possible signs of a severe allergic reaction:
- • Red, itchy raised rash (also called weals or hives)
- • Itchy, watery eyes
- • Swelling of the face or lips
- • Vomiting or diarrhoea
- • Their breathing may become difficult or wheezy
- • They may become pale or be very flushed
- • They may become agitated
What to do – severe allergic reaction in babies
If you think your baby is having an allergic reaction, you need
to get help as soon as possible.

1. Dial 999/112 straight away. Tell them you think your baby is
having a severe allergic reaction and what might have caused
it.
2. If you already know what your baby is allergic to and have
medication to treat an allergic reaction, give it to them as you
have been instructed.
3. Sit them on your lap leaning forwards slightly, to help their
breathing while you are waiting for help. If they appear to be in
shock, lie them down.
4. If they become unresponsive and are no longer breathing
normally be prepared to start CPR.