Urticaria

Urticaria, commonly called hives, is a skin condition in which itchy raised bumps or patches appear when chemical mediators released in the skin cause swelling. Hives are common, and people with other allergies are more likely to develop them. Triggers include certain foods, medicines, insect bites or stings, infections, immune system problems, emotional stress, cold, heat, sweating, pressure on the skin, and contact with plants, animals, chemicals or latex. The rash can appear anywhere, may affect one area or spread widely, and can itch, sting or burn, with colour changes less visible on darker skin. Swelling beneath the skin (angioedema) can accompany hives, and rarely airway swelling makes breathing difficult, which is an emergency. Antihistamines are the usual medicines for symptom relief, doctors may add topical cooling preparations or steroid tablets, and a serious case may need an injection.

Seek urgent care for a rapidly spreading rash with fever, a rash with blisters or peeling, or facial swelling. See a doctor for skin changes that do not improve with over-the-counter treatment after a few weeks, a mole that changes, or acne that is scarring or affecting your confidence. Call the local emergency number for any symptom that is sudden and severe. This page is a reference for healthcare professionals and does not replace an assessment.