Hives (Urticaria)

General Description

Surely all of us know at least one person (maybe even ourselves) who, after ingesting a certain food or medicine, has broken out in itchy bumps and patches. The condition is called urticaria, and it is a very common one, affecting over 15 percent of the population at some time during their lives.

Urticaria begins as a sensation of itching in a localized area. Minutes later the hive (or wheal) arises, lasting for minutes or hours before vanishing without a trace. Subsequent hives may appear anywhere else on the body, including the lips, mouth, genitals, and eyelids. Some hives may be induced by light pressure applied to the skin (dermatographism). Hives are caused by fluid leaking out of blood vessels located under the skin surface. Increased permeability of these vessels is the result of a chemical (histamine) released from specialized cells circulating in the blood stream.

Anaphylaxis is the most serious form of urticaria. Here the reaction is so widespread that even the throat and lungs are affected, swelling up and filling with fluid. Breathing may become impossible, and death from asphyxiation can result. Anaphylaxis is a life-threatening medical emergency.

Causes

Urticaria represents an allergic response and is most frequently caused by drugs, such as aspirin and penicillin; foods, with the most common being strawberries, shellfish, peanuts, and tomatoes; and insect bites, such as bee stings. At times the allergic agent (allergen) is difficult to track down; for instance, some cases of urticaria have been linked to food preservatives and dyes, others to hidden infection within the body (in these cases the body becomes allergic to certain germs or parasites). Some persons break out with hives when emotionally upset or when under stress.

If the cause of hives is not immediately known, one would do well to keep a detailed diary recording every single food item and drug that one ingests (including even over-the-counter preparations like aspirin). A record should also be made of each new wheal. Reviewing such a diary might enable one to pinpoint the allergen causing the hives.

Medical Treatments

People prone to or suffering from hives should avoid ingestion of citrus fruits, shellfish, and products containing aspirin, all of which can cause or worsen this condition. Such individuals should exercise caution when taking prescribed antibiotics, most notably penicillin and ampicillin, and would do well to notify a physician at the first sign of a rash.

The itching of hives may be relieved by cool-water or ice-water compresses. Oatmeal or cornstarch baths are quite soothing. Hives are treated medically with antihistamines. These compounds (including Benadryl, Atarax, and Phenergan) will often decrease or terminate the annoying symptoms. The major side effect from antihistamines is drowsiness, and one should drive and operate machinery with care. Often a better option is non-sedating agents such as Allegra, Clarinex, Claritin, Zyrtec, and Xyzal. Some acute and/or persistent cases may also require oral or injectable steroid therapy. Persons experiencing wheezing or shortness of breath (anaphylaxis) must be rushed to the nearest doctor’s office or hospital; a shot of epinephrine (adrenaline) may prove lifesaving.