Question:

Any information you have about hives in adults will be greatly appreciated.

Answer:

About one in five people will experience hives (known medically as urticaria) at some point in their lives. Most often hives are the result of an allergic reaction, which causes release of histamine and other chemicals into the bloodstream and tissues. Hives can affect anyone at any age.

Urticaria appears on the surface of the skin as swollen, red, itchy welts that vary in size. They sometimes have a white center and often join together to form large, irregular patches, which can pop up in a small area or cover your entire body.

In addition to the welts, people sometimes complain of fatigue, fever and nausea soon after hives appear. Trouble breathing, wheezing or faintness closely following the onset of hives indicates an emergency situation requiring immediate medical attention.

Urticaria can be triggered by certain foods, particularly shellfish, tomatoes, strawberries, eggs, milk or chocolate. Pollen, animal dander, insect bites, food dyes, mold, cold and hot weather, exposure to sunlight and even vigorous exercise are also known culprits. Allergy testing to pinpoint specific allergens that cause a skin reaction can be performed by a dermatologist or an allergist. Tension and stress are also associated with the appearance and persistence of urticaria.

Many infections can cause hives. Colds, for instance, are a common cause of hives in children. Prescriptions and over-the-counter medications can cause urticaria including antibiotics, pain medications, sedatives, tranquilizers and diuretics (fluid pills). Diet supplements, antacids, arthritis medication, vitamins, eyedrops and eardrops, and laxatives also can be a potential cause of hives.

Hives lasting less than six weeks are called "acute" urticaria, and the cause can usually be found. The most common causes are foods, drugs, or infections. Insect bites and internal disease also may be responsible.

"Chronic" urticaria is diagnosed when hives last longer than six weeks. Many cases of chronic urticaria are diagnosed as idiopathic, which means the cause or origin of the condition cannot be found. For most people with chronic urticaria, the condition lasts for several months or years.

"Urticarial vasculitis" refers to when individual hives persist in one location for more than 24 hours. These cases are commonly linked to chronic infections (urinary tract infections or hepatitis B or C, for example) or disease (such as rheumatoid arthritis or lupus).

The best treatment for hives is to find and remove the cause, when possible. Taking cool baths or showers, wearing light, loose clothing and minimizing vigorous activity often helps to speed recovery. Over-the-counter antihistamines, such as Benadryl, as well as prescription antihistamines, typically provide immediate relief from the itching.

In severe hives, an injection of epinephrine (adrenalin) or a cortisone medication may be needed. Topical corticosteroid creams are helpful, as well. However, these creams should be prescribed by your dermatologist, since prescription cortisone cream's potency is almost 2,000 times greater than over-the-counter hydrocortisone creams.

For more information about urticaria, visit the American Academy of Dermatology Web site.