Hives, or urticaria, usually occur as part of an allergic reaction that causes a substance called histamine to be released as part of your body's natural immune response. Histamine, in turn, causes welts or bumps to appear on the skin's surface, or sometimes, in the mouth and throat. Some common causes of hives include:
detergents, soaps, and toiletries
plants or molds
Sometimes, hives can be caused by other factors, like stress, metabolic disease or infections.
Hives can produce sensations like itching, burning, tingling or stinging. When they occur inside the mouth or throat, they can cause the throat or mouth to itch and can even cause swelling that can interfere with breathing. If you develop hives in your mouth or throat, you should seek medical care immediately. Hives usually fade away within a few hours, but sometimes they can last longer. A single hive may be quite small, but they usually form in patches called plaques.
Treatment begins with a complete health history and review of your symptoms, including asking about the activities you were performing just before the hives appeared. In most cases, hives can be successfully treated with antihistamine medications to help control the body's immune reactions. Cool compresses can help reduce itching and burning sensations. If antihistamines do not bring relief, corticosteroid medications may be prescribed, either on their own or in addition to antihistamines. Epinephrine injections may be used if the hives impede breathing. If hives occur chronically or occur in the mouth or throat and the cause cannot be determined from your health history, allergy testing may be ordered to determine the trigger.