Hives information from trusted sources:
Urticaria
Hives are red and sometimes itchy bumps on your skin. An allergic reaction to a drug or food usually causes them. Allergic reactions cause your body to release chemicals that can make your skin swell up in hives. People who have other allergies are more likely to get hives than other people. Other causes include infections and stress. Hives are very common. They usually go away on their own, but if you have a serious case, you might need medicine or a shot. In rare cases, allergic reactions can cause a dangerous swelling in your airways, making it hard to breathe - which is a medical emergency.
Hives
Hives are raised, often itchy, red welts on the surface of the skin. They are usually an allergic reaction to food or medicine.
Urticaria
Nettle rash (also known as urticaria, hives or welts) is a raised, red, itchy rash that appears on the skin. Urticaria happens when a trigger, normally an allergen (something that produces an allergic reaction) causes the body to release histamine, a protein in our body. Histamine causes tiny blood vessels, known as capillaries, to leak fluid. The fluid then gathers in our skin and causes a rash.
Urticaria
Hives (urticaria), also known as welts, is a common skin condition with an itchy rash of pink to red bumps that appear and disappear anywhere on the body. An individual lesion of hives typically lasts a few hours before fading away, and new hives can appear as older areas disappear.
Chronic hives
Chronic hives, also known as urticaria, are batches of raised, red or white itchy welts (wheals) of various sizes that appear and disappear. While most cases of hives go away within a few weeks or less, for some people they are a long-term problem. Chronic hives are defined as hives that last more than six weeks or hives that go away, but recur frequently.
Hives and Angioedema
Hives is an allergic skin reaction that comes on suddenly. The hives themselves are slightly raised, smooth, flat-topped bumps called wheals (look like mosquito bites) and welts that are usually more red in color than the surrounding skin and cause severe itching. Angioedema is like hives, only the welts are larger and form at a deeper layer in the skin. This causes severe swelling, usually in the face, near the eyes and mouth. The swelling can also occur in the inside of the throat, which is a dangerous situation because it can close off the passage of air into the lungs.