Hives (urticaria)
Hives are raised, itchy, red or skin-coloured welts that appear suddenly and usually fade within 24 hours, while new ones may appear elsewhere. They are often caused by an allergy or an infection, but in many people no cause is found. Most cases go away within days or weeks. Hives with swelling of the lips or tongue, or trouble breathing, is an emergency.
Symptoms
- Raised itchy welts that may join together
- Welts that move around and fade within hours
- Red or skin-coloured swelling with a pale centre
- Swelling of the eyelids, lips, hands or feet in some people
- Burning or stinging of the skin
Causes
- Allergy to foods such as eggs, nuts, fish or strawberries
- Medicines such as antibiotics, aspirin or other painkillers
- Viral infections, especially in children
- Insect stings or bites
- Heat, cold, pressure on the skin or sweating
- In long-lasting hives, often no cause is found
Prevention
- Avoid foods or medicines that caused hives before
- Keep a diary to find possible triggers
- Tell every doctor and pharmacist about medicine allergies
- Wear loose clothing and avoid very hot showers if heat triggers hives
Treatment
- Non-drowsy antihistamine tablets such as cetirizine or loratadine are the main treatment
- Cool compresses and calamine lotion may ease itching
- Stop any medicine that may have caused it, after checking with a doctor
- A short course of steroid tablets only if a doctor decides it is needed
- Adrenaline injection in hospital for severe allergic reactions
Common questions
Are hives contagious?
No. Hives are a reaction of your own skin and cannot be passed to other people.
Why do my hives keep coming back for months?
Hives lasting more than 6 weeks are called chronic hives. Often no allergy is found and the immune system is overactive. Daily antihistamines usually control it, and it often settles within a year or two.