Hives (Urticaria) Guide

Hives (urticaria) are raised, itchy welts that appear on the skin when the body releases histamine into the bloodstream. They affect roughly one in five people at some point. The welts can be small or large, appear anywhere on the body, and often shift location over hours.

Most cases are acute, meaning they resolve within a few weeks. Chronic urticaria — where hives persist for longer than six weeks — is less common but can be frustrating to live with. Both respond well to treatment once triggers are identified and the right antihistamine regimen is found.

Common triggers

Acute urticaria is often triggered by viral infections, particularly in children. Allergic reactions to foods (shellfish, nuts, eggs), medications (NSAIDs, antibiotics), insect stings, and latex are also frequent causes. Contact with certain plants, chemicals, or even cold water can produce hives in susceptible people.

Physical triggers include pressure on the skin (dermatographia), heat, exercise, and sunlight. These are grouped under the term "inducible urticaria" and account for a significant proportion of chronic cases.

In about half of chronic urticaria cases, no specific trigger is found. This is called chronic spontaneous urticaria. It's thought to involve autoimmune mechanisms where the body's own antibodies activate mast cells in the skin.

Treatment

First-line treatment is a non-sedating antihistamine such as cetirizine, loratadine, or fexofenadine. These block histamine receptors and reduce itching and swelling. They work best when taken regularly rather than just when symptoms appear.

If a standard dose isn't enough, BSACI guidelines support increasing to up to four times the normal dose before moving to other treatments. This higher dosing is safe for most adults but should be discussed with your doctor.

For severe or resistant cases, a short course of oral corticosteroids (prednisolone) may be used to bring a flare under control. Long-term steroid use is avoided due to side effects. Omalizumab, a monthly injection that targets IgE antibodies, is available through specialists for chronic urticaria that doesn't respond to antihistamines.

Cool compresses, loose clothing, and avoiding known triggers are practical measures that complement medication. Keeping a symptom diary can help identify patterns you might otherwise miss.

When to investigate further

If hives last longer than six weeks, blood tests can help exclude underlying conditions. Thyroid autoimmunity is found in 10-27% of chronic urticaria patients. A full blood count checks for infection or blood disorders. Inflammatory markers (CRP, ESR) screen for systemic inflammation.

Allergy testing (skin prick tests or specific IgE blood tests) is useful when there's a clear pattern linking hives to particular foods, animals, or environmental exposures. It's less useful for chronic spontaneous urticaria where no obvious trigger exists.

How we can help

We offer same-day GP appointments for acute hives, with antihistamine prescriptions available immediately. For chronic or recurrent urticaria, we can arrange blood tests on-site and refer to allergy specialists or dermatologists if needed.

Our allergy testing service covers a comprehensive panel of common allergens and can help pinpoint triggers when there's a suspected allergic cause.