Urticaria

Urticaria, or hives, produces raised, intensely itchy welts that typically come and go within 24 hours. Deeper swelling of the lips or eyes, called angioedema, may accompany them.

Acute hives often follow an infection, medication, or food. Chronic hives, lasting more than six weeks, are usually not allergic and respond well to structured antihistamine therapy or, when needed, biologic treatment.