Hives are characterized as itchy flesh-colored or pink/red, raised welts (also known as wheals) on the skin's surface that can join together and form larger areas of raised lesions. By definition, the lesions should appear and leave within 24 hours.

Hives are a result of the leakage of fluid from small blood vessels in the skin in response to an immune response. The cause of hives is most often not found. In fact, most patients with hives never have an identified culprit. Rarely, they are a result of an allergic reaction to food, medications or exposure to environmental allergens such as trees, grasses or animals. Very rarely, they can also be triggered by sun exposure, stress, excessive perspiration or other, more serious diseases, such as lupus. Hives may itch, burn or sting. They rarely need medical attention as they tend to disappear on their own. However, in persistent cases, your provider may prescribe antihistamines (the best option) or oral corticosteroids (for severe episodes). Those who experience hives may be at risk for more serious allergic responses and therefore a visit to a health care professional may be warranted.

Patients with hives lasting more than six weeks are diagnosed with chronic urticaria. Allergists may be consulted to evaluate chronic hive patients. If there is swelling deeper below the surface of the skin, angioedema can result. This is a more dramatic swelling often causing a lip to balloon in appearance, or an eye to swell shut. Cases of angioedema are most often managed by an allergist.