Extreme Hives: What You Should Know

Hives, also called urticaria, are itchy, raised patches that may appear suddenly and change shape or location. Individual welts often fade while new ones form. Triggers can include foods, medicines, infections, heat, pressure, or contact with an irritant, although a clear trigger is not always found.

Marked swelling beneath the skin, especially around the lips, eyelids, tongue, or throat, is called angioedema and can occur with hives. See [Hives](/conditions/urticaria/) for the broader condition and [Angioedema](/conditions/angioedema/) for deeper swelling.

Stop using any newly introduced skin product and make a note of recent foods, medicines, infections, heat exposure, or insect contact. Avoid scratching, hot showers, and tight clothing; a cool compress and loose, soft clothing may reduce irritation.

A clinician may recommend an oral antihistamine to reduce itch and wheals; follow the product instructions and check before using it if you are pregnant, treating a child, or taking other medicines. In selected severe episodes, an oral corticosteroid may be prescribed for a short course. Read about [Antihistamine Treatment](/treatments/medical-dermatology/oral-antihistamine-therapy/) and [Oral Corticosteroid Treatment](/treatments/medical-dermatology/oral-corticosteroid-therapy/).

Call emergency services immediately for trouble breathing, wheezing, throat tightness, difficulty swallowing, faintness, confusion, or rapidly increasing swelling of the tongue or face. These symptoms can accompany a serious allergic reaction; do not wait for the rash to settle.

Arrange prompt medical evaluation when hives are extensive, keep returning, interfere with sleep, or come with fever, painful lesions, bruising, vomiting, or swelling. If the rash is itchy without emergency symptoms, [Itchy Skin](/symptoms/itchy-skin/), [Skin Rash](/symptoms/skin-rash/), and [Skin Swelling](/symptoms/skin-swelling/) offer related explanations.

Ask which triggers or medicines should be avoided, whether your symptoms suggest angioedema, how long to use a recommended antihistamine, and what warning signs should send you to emergency care. Bring photos of changing welts and a list of recent exposures.