Urticaria (hives) are welts on the skin that often itch. These welts can appear on any part of the skin. Hives vary in size from as small as a pen tip to as large as a dinner plate. They may connect to form even larger welts.
 
A hive often goes away in 24 hours or less. New hives may appear as old ones fade, so hives may last for a few days or longer. A bout of hives usually lasts less than 6 weeks. These hives are called acute hives. If hives last more than 6 weeks, they are called chronic hives.   Acute hives often result from an allergy, but they can have many other causes.
 
For a mild or moderate case of hives, the most common treatment is a non-sedating (does not cause drowsiness) antihistamine. Antihistamines relieve symptoms like itching. If you have chronic hives, your dermatologist may prescribe an antihistamine combined with other medicines to control the hives. Make an appointment to find the right solution for you.