Urticaria (Hives)

Definition

Urticaria is called medically as hives. Urticaria is also known as nettle rash or uredo. It is a relatively common form of allergic reaction that causes raised red skin welts. These welts can be 5 mm in diameter or more, itch severely, and often have a pale border. Urticaria is generally caused by direct contact with an allergenic substance, or an immune response to food or some other allergen. Hives can be caused by stress. The weal can be a few millimeters or several centimeters in diameter, colored white or red, often surrounded by a red flare, and frequently itchy. Each weal may last a few minutes or several hours, and may change shape. Weal may be round, or form rings, a map-like pattern or giant patches. An episode of hives may last from a few minutes to several hours to several days to several weeks. Each individual welt should last no more than 24 hours.

Causes

1. Allergic reaction to some medicines can cause urticaria. Some of the medicines are anti-inflammatory drugs, and antibiotics especially penicillin and aspirin.
2. Some foods are also allergic to some persons and can cause urticaria. Some food are nuts, eggs, chocolate, citrus fruits, strawberries, shellfish and food additives.
3. Bee or wasp stings may cause urticaria.
4. Certain viral infections such as glandular fever and hepatitis B or blood transfusions can also cause hives.
5. It may result from digestive disorders like mechanical irritation in the digestive tract or toxaemia.
6. It may also result from emotional excitement or intense stress.

Symptoms

1. Hives usually appear first on the covered areas of the skin such as the trunk and upper parts of the arms and legs.
2. Hives are usually comes as spot on body. But they merge together to make patches on body.
3. Hives flare, itch, swell, and go away in a matter of minutes to hours. This sequence may go on from days to weeks. Most hive episodes last less than six weeks. Chronic hives last more than six weeks.
4. The itching is often very intense.
5. Swelling of the face, tongue, or throat may occur.

Treatment

1. The food which is causing the problem should be avoided such as nuts, eggs, chocolate, citrus fruits, strawberries or shellfish.
2. High doses of antihistamines may be necessary for prolonged periods of up to six weeks.
3. Limiting outdoor exposure, shutting windows, avoiding the drugs that are identified to be allergic.
4. Steroids have limited use in most patients with acute urticaria. In individuals who have persistent or recurrent attacks of acute urticaria, they may respond to steroid therapy. Steroids should only be used after a trial of maximal dose of antihistamines.
5. Topical therapies for hives include creams and lotions which help numb nerve endings and reduce itching. Some ingredients which can accomplish this are camphor, menthol, diphenhydramine and pramoxine.
6. When other options fail, corticosteroids may be used to suppress the immune system in chronic urticaria or for frequently recurring episodes.