What should you know about white hives?

Hives can appear as separate bumps or larger connected patches. They may change shape, move to another area, or fade while new welts appear elsewhere. Scratching, heat, pressure, infection, medicines, foods, or contact triggers can be relevant, but the colour alone cannot identify the cause. Deeper swelling of the lips, eyelids, hands, or other areas may occur with angioedema.

Note when the welts started, how long each individual mark lasts, whether they itch or burn, and whether anything new touched or entered your body.

Use cool compresses, wear loose clothing, and avoid rubbing or hot showers while the skin is active. Photograph the rash in natural light when it is visible. A pharmacist or clinician can advise whether an oral antihistamine is suitable and how to use it safely; do not borrow prescription medicines or add a corticosteroid without advice.

Seek emergency help for trouble breathing, throat or tongue swelling, faintness, confusion, or difficulty swallowing. Arrange prompt medical assessment if swelling is rapidly increasing, the rash is painful rather than itchy, marks stay fixed in one place, or fever or significant illness accompanies it. Recurrent hives that disrupt sleep or daily activities deserve a planned review.

Could this be hives or another rash? Which triggers, medicines, or infections should I review? Is an antihistamine appropriate for me? What changes would mean I need urgent help?