Hives is a term used to describe an itchy skin rash. The medical term for this is urticaria.
Hives are itchy, raised, red bumps that appear on the skin. They may appear anywhere on the body. They can move around , with the older lesions settling and newer lesions appearing. Usually they last for several days .
A lot of people will assume this type of rash to be an allergy. However they are a wide variety of causes.
The rash is caused by the release of histamine for cells in the skin.
In many cases a cause is not identified.
Mostly when we are talking about urticaria we are talking about acute urticaria. By this we mean a rash that will settle in a few days or weeks. Some people develop a condition called chronic urticaria. In some of these people, it may be due to an autoimmune cause. In this instance, their own body makes antibodies which are directed against the mast cells(cells which release histamine) in their skin. We treat this in the same way we would treat other causes.
If there is a known trigger this should be avoided.
Often treatment is not necessary as the rash will settle in a few days.
Antihistamines are prescribed if the itch is troublesome. There are a variety of these available over the counter.
Sometimes if symptoms are severe or persistent your doctor may prescribe a steroid cream or tablet.