The main symptom of hives (urticaria) is a rash.

The rash may:

  • be raised
  • be very itchy
  • be on one part of the body
  • spread over large areas
  • range is size from a few millimetres to the size of a hand
  • change in appearance within 24 hours
pale, circular red blotches of skin
The image shows a hives rash on the side of the stomach. The rash is small, circular patches of pink on pale skin.
More images of hives

Image 1

Large, red, blotchy rash all over male chest

Image 2

Small, red blotches on pale forearm

Image 3

Large red blotches on back of child's shoulder

Diagnosing hives

Hives can usually be diagnosed by examining the distinctive red rash. The pharmacist or GP may also ask you questions to find out what triggered your symptoms.

If your symptoms last a while (chronic urticaria), a doctor may arrange for tests to help work out the cause. They'll also ask about anything that makes your symptoms worse.

Treating hives

Most hives rashes don't need treatment. The symptoms are usually mild and often get better within a few days.

If necessary, a pharmacist can give you advice about antihistamines to help treat hives.

Antihistamines may not be suitable for young children or if you've got a long term condition. You should discuss this with the pharmacist.

Treating severe hives

If hives are more severe, your doctor may prescribe:

If hives don't go away with treatment, a doctor may also refer you to a skin specialist (dermatologist).

Immediate action required: Phone 999 or go to A&E if you:

  • have swelling in your mouth, eyes, face, lips, tongue, throat, feet or hands
  • are wheezing
  • feel lightheaded or faint
  • get tightness in your chest or throat
  • have trouble breathing or talking
  • have abdominal pain, nausea and vomiting

You could be having a serious allergic reaction (anaphylaxis) and may need immediate treatment in hospital.

Non-urgent advice: Speak to a GP if:

  • the symptoms don't improve after 2 days
  • you're worried about your child's hives
  • the rash is spreading
  • the symptoms are severe
  • hives keeps coming back (you may be allergic to something)
  • you also have a high temperature and feel unwell
  • you also have swelling under your skin (this might be angioedema)
  • the symptoms cause distress
  • the symptoms disrupt daily activities

Causes of hives

Hives occur when histamine and other chemicals are released from under the skin's surface. This causes the tissues to swell.

Histamine can be released for many reasons, including:

  • eating certain foods
  • an insect bite or sting
  • cold – including exposure to cold water or wind
  • heat – including from exercise or eating spicy food
  • emotional stress
  • an infection like a cold
  • having drinks like alcohol or caffeine
  • taking medicines like non-steroidal anti-inflammatory drugs (NSAIDs) or antibiotics
  • a reaction to environmental factors like pollen, dust mites or chemicals
  • an allergic reaction to latex
  • scratching or pressing on your skin – like wearing itchy or tight clothing
  • a problem with your immune system
  • water or sunlight (though this is rare)

If you can, try to work out what's causing your hives. This can help to avoid them in the future.

Self-help guide

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Complications of hives

Complications of hives can include:

  • angioedema – a deeper swelling of tissues
  • psychological and emotional problems like stress and anxiety
  • anaphylaxis – a severe allergic reaction that should be treated as a serious medical emergency

Last updated:
29 May 2023

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