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Allergic reactions: What you need to know

Healthy eating
  • Date published:

  • Author: oliverkyle

Allergic reactions happen when the immune system – the body's natural defence system – overreacts to something which is usually harmless like pollen, dust or animal fur. Symptoms can be mild, but for some can be very serious.

Things that cause allergic reactions are called allergens. They can cause symptoms such as a runny nose, sneezing, itchy skin, rashes and diarrhoea.

Common allergens include:

  • Foods – including nuts, milk, fish, shellfish, eggs and some fruits
  • Medicines – including some antibiotics and certain drugs such as aspirin
  • Insect stings– particularly wasp and bee stings
  • Dust mites
  • Tree and grass pollen (hay fever)
  • Animal fur – particularly from cats and dogs
  • General anaesthetic
  • Chemicals such as hair dye
  • Latex

In some cases, there’s no obvious trigger.

If you suspect your child has an allergy contact their GP and make your child’s school are aware of any suspected or confirmed allergies.


Severe allergic reactions (anaphylaxis) can be life-threatening and should be treated as a medical emergency. Symptoms include:

  • Swelling of the tongue and throat
  • Difficulty breathing or breathing very fast
  • Difficulty swallowing, tightness of the throat or a hoarse voice
  • Wheezing, coughing or noisy breathing
  • Feeling lightheaded, dizzy or faint
  • A fast heartbeat
  • Clammy skin or skin that feels cold to the touch
  • Confusion and anxiety
  • Collapsing or losing consciousness
  • Blue, grey or pale skin, lips or tongue – on brown or black skin, this may be easier to see on the palms of the hands or soles of the feet
  • A child who is limp or floppy or not responding how they usually do

It is important use an adrenaline auto-injector (if available) and call 999 if you suspect somebody is having a severe allergic reaction. Click here for more information.

If your child has a serious allergy or has experienced an allergic reaction before, it’s important to take steps to prevent it happening again:

  • See if you can identify any triggers – your child may be referred to an allergy clinic for tests to check for anything that could trigger allergic reaction
  • Avoid these triggers whenever possible – for example, by being careful when food shopping or eating out if your child has a food allergy, or by ensuring they wear long sleeves if insect stings are a problem

People with potentially serious allergies will often be given an adrenaline auto-injector to carry at all times. This can help stop an allergic reaction becoming life threatening.

It should be used as soon as a serious reaction is suspected, either by the person experiencing anaphylaxis or someone helping them.

If you have been given an auto-injector for your child, make sure you know how to use it correctly and always carry it. Don’t be afraid to use it whenever you think your child may be having an allergic reaction, even if you’re not completely sure as this will not harm your child.

There are two main types of adrenaline auto-injector, which are used in slightly different ways. These are:

  • EpiPen
  • Jext

If your child suffers from an allergy, it’s important to tell your child’s school and school nurse. Your child will have a personal care plan given to them by their doctor and it’s important that their school has a copy of this.

The school will not be able to use the auto-injector without a care plan in place.

Further support and advice is available from the following: