What should you know about large hives?

Hives are raised areas caused by temporary release of inflammatory chemicals in the skin. Individual welts may be pale, pink, or red and can join together into larger patches. Itch is common, and deeper swelling may affect the eyelids, lips, hands, or other areas. Triggers can include infections, medicines, foods, heat, pressure, or may remain unclear. A rash that stays fixed in one place, bruises, blisters, or causes significant pain may need a different diagnosis.

Move away from a suspected trigger when possible, keep the skin cool, and avoid hot showers, tight clothing, and vigorous rubbing. A clinician or pharmacist may advise an oral antihistamine, while other treatment is selected according to severity and medical history. Do not take a medicine previously linked to a reaction without professional advice. Photographing the rash and recording recent foods, medicines, illness, heat, or pressure can help with assessment.

Call emergency services immediately for trouble breathing, wheezing, throat tightness, difficulty swallowing, voice change, dizziness, collapse, or rapidly increasing swelling of the tongue or mouth. These symptoms can occur with a serious allergic reaction. Seek prompt medical advice for extensive hives, repeated episodes, severe discomfort, or swelling without a clear trigger, even when breathing is normal.

Ask what may have triggered the episode, whether the swelling suggests angioedema, which antihistamine plan is appropriate, what to avoid, whether you need an emergency action plan, and when recurring hives require specialist review.