What should you know about spontaneous hives?

Hives, also called urticaria, form when skin cells release inflammatory chemicals. Individual welts may change shape, fade, and reappear elsewhere while the episode continues. Heat, pressure, infection, medicines, foods, or stress can be involved, but a clear cause is not always found. Itchy skin and a blotchy rash commonly accompany hives. Deeper swelling around the lips, eyelids, hands, or feet is called angioedema and can occur with hives.

A clinician may ask when the welts began, how long each mark lasts, what medicines or foods preceded them, and whether breathing or swallowing changed. Take clear photographs because the skin may look different during an appointment.

Keep the skin cool, wear loose clothing, and avoid rubbing or scratching the welts. A cool compress can calm the itch. Write down new medicines, supplements, foods, illnesses, heat exposure, and pressure from clothing so patterns are easier to recognise. A pharmacist or clinician can advise whether an oral antihistamine is suitable and how to use it safely. Do not stop a prescribed medicine without discussing it with the prescriber. Oral corticosteroids may be considered by a clinician for selected severe episodes, but they are not a routine self-treatment.

Seek emergency help immediately if hives occur with swelling of the tongue or throat, trouble breathing, wheezing, faintness, confusion, or difficulty swallowing. These symptoms can signal a severe allergic reaction. Arrange medical review when episodes keep returning, swelling is painful, a mark stays in one place unusually long, or bruising, fever, or feeling unwell accompanies the rash. Bring photographs and a list of recent exposures.

Could this be hives, angioedema, or another rash? Which triggers should I record? Is an antihistamine appropriate for me, and what warning signs require emergency help?