Causes of hives or urticaria
Hives or urticaria can develop when the body releases histamines as part of an allergic reaction. The histamines make small blood vessels in the skin open up and leak fluid, which forms raised red blotches on the skin surface.
Your child might have an allergic reaction to:
- certain types of foods - for example, nuts, eggs, shellfish, strawberries, tomatoes and cow's milk
- food colourings, spices and preservatives
- medicines - for example, penicillin
- insect bites - for example, bee or wasp stings.
Viral infections like those that cause colds or diarrhoea can also cause hives in children.
Your child might also develop itchy skin (with or without hives spots) because of heat, or tight-fitting or scratchy clothing, particularly if your child has eczema (dermatitis). This is a kind of physical irritation of sensitive skin, not an allergy.
Hives are very common but not contagious.
Symptoms of hives or urticaria
It might take days or weeks for hives to develop.
Your child will probably complain of a really bad itch and lumps. You'll see small, raised, white, pink or red spots that can merge together to form large patches anywhere on the skin.
True hives last between a few hours and 24 hours. When they go, there's no scarring.
When to see your doctor about hives or urticaria
You should see your doctor if:
- your child's lips or tongue swells
- your child has trouble breathing or is wheezing
- your child is generally unwell or has a fever in addition to the hives
- the hives come up straight after your child takes any sort of medicine
- the hives keep coming back for longer than six weeks
- your child is itchy, uncomfortable or finding it hard to sleep because of the hives.
Treatment for hives
Rubbing and scratching the hives will make them worse. Try to get your child to stop scratching.
To relieve the itch, you can apply lots of calamine lotion to the hives and let it dry. Putting cold packs on the hives or giving your child a cool shower or bath can also help.
Your GP might suggest using antihistamine medication until the hives get better. It's best to take the antihistamine regularly until the rash clears. If your child is under two years, make sure you use a non-drowsy antihistamine. If you're not sure which antihistamine to use, ask your pharmacist.
If the hives keep coming back after your child stops taking the antihistamine, see your GP.
In severe cases of hives, the GP might prescribe a short course of corticosteroid tablets.
Prevention of hives or urticaria
Try to work out what has caused your child's allergic reaction. This way, your child can keep away from it in the future.
Talk to your GP if you think your child might need allergy testing. Your GP might refer you to a paediatric dermatologist or allergy and immunology specialist.