What should you know about itchy welts?

Hives, also called urticaria or a nettle rash, are temporary raised patches caused by the release of inflammatory chemicals in the skin. They may be pink, red, or close to your natural skin tone, and can occur anywhere on the body. Individual welts often change shape or position rather than staying fixed in one place.

Triggers can include an infection, a medicine, a food, heat, cold, pressure, exercise, or emotional stress, although a clear trigger is not always found. Deeper swelling around the lips, eyelids, hands, feet, or throat is called angioedema and may occur with hives. Itchy skin and a skin rash can have other causes, so a persistent or unusual pattern deserves assessment.

Note when the welts began, how long each one lasts, what areas are affected, and any recent medicines, foods, illnesses, heat exposure, pressure, or new products. Keep the skin cool, wear loose clothing, and avoid scratching or rubbing the raised areas. A pharmacist or clinician can advise whether an oral antihistamine is suitable for you and how to use it safely.

Arrange a medical review if the welts keep returning, continue for several days, leave bruising or pain, or interfere with sleep. Bring a list of medicines and a photograph taken during a flare; the appearance may have changed by the time you are examined.

Seek emergency help immediately for swelling of the tongue, mouth, or throat; trouble breathing or swallowing; wheezing; faintness; confusion; or rapidly worsening symptoms. These signs can indicate a serious allergic reaction, especially when they begin soon after a food, medicine, or sting.

Get prompt medical advice for widespread skin swelling, fever, significant pain, blistering, or welts that appear bruised or purple. Do not wait for a rash to settle if you feel very unwell or if the face and airway may be involved.

Ask: Could these marks be hives or another type of rash? Could a medicine, infection, pressure, heat, or food be contributing? What symptoms should make me seek emergency help? Which treatment is appropriate with my other medicines or health conditions?