Hives and skin allergy

Hives are also called urticaria. They form when signals in the skin cause small blood vessels to leak fluid into nearby tissue, producing raised, itchy welts. An allergy to a food, medicine, or insect sting can trigger this response, but infections, heat, pressure, or other non-allergic causes can do the same. A skin reaction alone cannot identify the trigger. Hives may appear with deeper swelling, called angioedema, around the lips, eyelids, hands, or feet. The pattern, timing, and associated symptoms help a clinician assess what is happening.

Stop further contact with a suspected cosmetic, food, or environmental trigger and wash exposed skin gently. Do not deliberately re-test a suspected food or medicine at home. Cool compresses and loose clothing may reduce discomfort. Ask a pharmacist or clinician whether an oral antihistamine is appropriate for you, especially if you have other medical conditions, are pregnant, or take regular medicines. Write down the product, meal, medicine, sting, illness, activity, and timing around the episode. Keep photographs because welts may fade before an appointment. A recurring pattern needs individual assessment rather than assuming every episode is an allergy.

Call emergency services immediately for breathing difficulty, wheezing, throat tightness, trouble swallowing, tongue swelling, sudden hoarseness, faintness, or collapse. These symptoms can indicate a severe allergic reaction. Seek prompt clinical advice after a new medicine or sting, with rapidly increasing facial swelling, or when vomiting, severe abdominal symptoms, fever, or marked illness accompanies the skin changes. Arrange review if episodes recur or the marks become painful, fixed, blistered, or bruise-like.

Ask whether the timing suggests an allergy, whether testing is useful, which antihistamine is safe for you, and how to make an emergency plan. Ask what to avoid until the cause is clearer.