Hives That Are Not Itchy: What to Know

Hives, also called urticaria, are temporary raised areas caused by signals from skin cells that widen nearby blood vessels and allow fluid into the skin. Itch is common but not required. Welts may feel warm, tight or tender, and they can be pale in the centre with a pink or red edge. A new medicine, infection, heat, pressure, exercise or contact with a trigger can precede an episode, although no clear trigger is often found.

Individual welts usually change shape or fade while new ones appear elsewhere. A mark that stays fixed, becomes bruised, forms blisters or leaves scaling may be a different kind of skin rash and deserves an examination.

Take a clear photograph and note when the welts began, where they appeared, recent foods or medicines, illness, heat, pressure and any swelling. Use cool measures, loose clothing and gentle, fragrance-free skin care. Avoid rubbing the area and do not stop a prescribed medicine without advice. A clinician may discuss an oral antihistamine treatment when symptoms need relief; treatment choice depends on your health, medicines and age.

Get emergency help immediately for swelling of the lips, tongue or throat, trouble breathing, wheezing, faintness, confusion or rapidly worsening symptoms. These can accompany angioedema or a serious allergic reaction. Arrange medical advice if the eruption keeps returning, lasts beyond a brief episode, follows a new medicine, or is painful, bruised or accompanied by fever. A clinician can distinguish hives from other causes of skin swelling.

Could these marks be hives rather than another rash? What triggers or medicines should I record? Which symptoms would change the urgency? Is an antihistamine suitable for me, and when would another treatment be considered?