Hives

What are hives?

Hives, also called urticaria, are raised, itchy rashes. They can be red or skin coloured. Hives usually come on suddenly as a reaction to an infection, food or medicine. Cells in your skin called mast cells react to the trigger by releasing histamine, which causes swelling, redness and itching.

Some people get a single rash on the body, others get symptoms on larger areas of skin. Not all itchy rashes are hives, they can also be dry skin, eczema or insect bites, for example.

Hives usually go away on their own within minutes to days, but if they last longer you might need treatment.

What do hives look like?

Hives are bright red or skin coloured and are often paler in the centre. They usually appear on the upper body, arms or legs. You might get one rash or several clusters covering large areas of your skin. They usually disappear within a few days and leave no marks.

What are the symptoms of hives?

Hives usually flare up quickly and can change both shape and location just as quickly. The rash might start to itch even before you can see it. The itching might feel like it’s burning or stinging.

Angioedema is swelling under the skin that sometimes occurs in combination with hives. It most often affects the face, for example the eyelids, mouth or throat. If you’re having trouble breathing, feel faint or pass out, call 999 or go to A&E.

What causes hives?

There are lots of possible triggers for hives. Sometimes you may be allergic to the trigger. 

Hives can be caused by:

• Eating certain foods (such as nuts, fish, shellfish, strawberries, cheese and wine)

• Coming into contact with certain vegetables or latex

• Insect bites and parasites such as wasp stings, bedbugs, scabies or intestinal parasites

• Physical triggers like cold or heat, sunlight, pressure, water and exertion

• Certain medications

• Stress or anxiety

• An infection like a UTI

Hives in children are usually caused by viral infections. They are particularly common with colds but can also occur with viruses such as coronavirus, which causes Covid-19. Hives in children can also be a reaction to foods such as eggs, milk protein, fish and nuts.

How to treat hives

Hives usually don’t need treatment and disappear on their own within a few days or weeks. Over-the-counter allergy medicines like antihistamines can help relieve your symptoms. Antihistamines aren’t suitable for everyone, so tell the pharmacist if you have any conditions. 

If your hives don’t go away or keep coming back, a doctor might need to investigate the underlying cause.

How to prevent hives

If you know what’s triggering your hives, avoid it as much as you can. Bear in mind that stress can sometimes trigger or worsen your symptoms.

When should I talk to a doctor about hives?

Make an appointment to speak to a doctor if:

• Your hives rash doesn’t go away after 2 weeks

• It keeps coming back

• The hives are spreading quickly 

• Your face has swollen

Call 999 or go to A&E if:

• You’re having trouble breathing 

• Your face is swelling

• You're having heart palpitations or your chest feels tight, your stomach hurts or you feel faint