What should you know about internal hives?

Hives, also called urticaria, result from chemical signals released in the skin. Welts may be pale, pink or red, and individual marks often change shape or location. Deeper swelling is called angioedema and can cause tightness, warmth or tenderness rather than surface itch. Episodes may follow an infection, pressure, heat, cold, food, medicine or another trigger, but a clear cause is not always found. Hives are not the same as an infection simply because the skin is red or swollen.

Note what happened before the episode, including new medicines, foods, illness, exercise or skin pressure. Cool compresses and loose clothing can reduce irritation. Avoid rubbing or scratching, which can provoke more welts. An oral antihistamine may ease itch and swelling when appropriate; follow the product instructions and ask a pharmacist about interactions or suitability. A clinician may use an oral corticosteroid for selected severe episodes, but it should not be started without medical guidance.

Call emergency services immediately for swelling of the tongue or throat, trouble breathing or swallowing, wheezing, faintness, sudden weakness or a rapidly worsening reaction. These signs can indicate anaphylaxis, even if the skin changes seem mild. Arrange medical review when episodes keep returning, last longer than expected, leave bruising, or occur with fever, joint pain or abdominal symptoms. Persistent skin swelling also deserves assessment so angioedema and other causes can be considered.

Could this be hives, angioedema or another rash? Which triggers should I record? What should I do if my lips or tongue swell? Is an antihistamine suitable with my current medicines?