Hives (Urticaria)

1. What does urticaria look like?

Hives are pink swellings called "wheals" that occur in groups on any part of the skin. Each individual wheal lasts less than a day before fading away, leaving no trace. When hives are forming they usually are very itchy, burn or sting. Hives are very common with 10 - 20 percent of the population having at least one episode in their lifetime.

2. What is acute urticaria?

The term acute urticaria is used for hives lasting less than six weeks. With this type of hives, the cause or causes can usually be identified and eliminated. The most common causes of hives are foods, drugs or infections. Insect bites and internal disease may also be responsible. Other causes can be physical stimuli, including pressure, cold, heat and sunlight.

Foods

The most common foods that cause hives are nuts, chocolate, fish, tomatoes, eggs, fresh berries and milk. Fresh foods cause hives more often than cooked foods. Food additives and preservatives may also be responsible. Hives may appear within minutes or up to two hours after eating, depending on where the food is absorbed in the digestive tract. For more detailed information  visit 'The Food and Allergy Network'

Drugs

Almost any prescription or over-the-counter medication can cause hives. Some of those drugs include antibiotics (especially penicillin and sulfa drugs), pain medications (especially aspirin), sedatives, tranquilizers and diuretics. Antacids, vitamins, eye and ear drops, laxatives, vaginal douches, or any other non-prescription item can be a potential cause of hives.

Infections

Many infections can cause hives. Viral upper respiratory tract infections are a common cause in children. Sinus, tooth or bladder infections can be a hidden cause.

3. What is chronic urticaria?

Episodes of hives lasting more than six weeks are called chronic urticaria. The cause of this type of hives is usually much more difficult to identify than that of acute urticaria. In studies of patients with chronic urticaria, the cause was identified in only a small percentage of patients.

4. What are physical urticarias?

Certain people can develop hives from sunlight, cold, pressure, vibration or exercise. Hives due to sunlight are called solar urticaria. This is a rare disorder in which hives come up within minutes of sun exposure on exposed areas and fade within one to two hours. Reaction to the cold is more common. Hives appear when the skin is warmed after exposure to cold. A simple test for this type of hives can be done by applying an ice cube to the skin surface.

The most common of the physical urticarias is called dermatographism. Hives form from firmly stroking or scratching the skin. It affects about 5 percent of the population. Most people with this condition are otherwise healthy. This condition can also occur along with other forms of urticaria. It may persist for months or even years.

5. What is the treatment for urticaria?

The best treatment for hives is to find the cause and then eliminate it. While investigating the cause of hives antihistamines are usually prescribed by your pediatrician to provide relief from itching. Antihistamines, such as Benadryl or Atarax, work best if taken on a regular schedule to prevent hives from forming. In severe cases of hives, oral cortisone or an injection of a cortisone preparation may bring dramatic relief.