HIVES (Urticaria; Giant Urticaria)

General Information

DEFINITION--An allergic disorder characterized by skin changes with raised areas, redness and itching.

BODY PARTS INVOLVED--Skin anywhere, including the scalp, lips, palms and soles.

SEX OR AGE MOST AFFECTED--Both sexes; all ages.

SIGNS & SYMPTOMS--

Itchy skin papules (small, raised bumps) with the following characteristics:

• They swell and produce pink or red lesions called wheals. Wheals have clearly defined edges and flat tops. They measure 1cm to 5cm in diameter.
• Wheals join together quickly and form large, flat plaques (larger areas of raised, skin-colored lesions).
• Wheals and plaques change shape, resolve and reappear in minutes or hours. This rapid change is unique to hives.

CAUSES--

Release of histamines, sometimes for unknown reason. Following are the most common causes:

• Medications. Nearly every drug causes hives in some persons.
• Insect bites; viral infections; autoimmune disease; dysproteinemias.
• Exposure to cold, heat, water or sunlight.
• Cancer, especially leukemia.
• Exposure to animals, especially cats.
• Eating eggs, fruits, nuts and shellfish. Other foods sometimes cause hives in infants, but not in adults.
• Food dyes and preservatives (possibly).
• Infection (bacterial, viral, fungal).

RISK INCREASES WITH

• Stress.
• Other allergies or a family history of allergies.

HOW TO PREVENT--Unpredictable, depending on the cause. If a medication or acute viral infection is responsible, hives usually disappear within hours or days. Some cases become chronic and last for months or years. Most eventually go into spontaneous remission even if the cause is not identified.

What To Expect

DIAGNOSTIC MEASURES--

• Your own observation of symptoms.
• Medical history and exam by a doctor.
• Diagnostic tests may include laboratory blood studies, urinalysis, erythrocyte sedimentation rate and chest x-ray to rule out inflammatory infection.

APPROPRIATE HEALTH CARE

• Self-care after diagnosis.
• Doctor's treatment.
• Emergency-room care for life-threatening reactions.
• Allergy skin tests and injections.

POSSIBLE COMPLICATIONS

• Swelling of the larynx and inability to breathe.
• Hives may be the first sign of life-threatening anaphylaxis. If so, it will be followed by itching, runny nose, wheezing, paleness, cold sweats and low blood pressure. Without prompt treatment, coma and cardiac arrest can occur.

PROBABLE OUTCOME--Unpredictable, depending on the cause. If a medication or acute viral infection is responsible, hives usually disappear within hours or days. Some cases become chronic and last for months or years. Most eventually go into spontaneous remission--even if the cause is not identified.

How To Treat

GENERAL MEASURES--

• Don't take drugs (including aspirin, laxatives, sedatives, vitamins, antacids, pain killers or cough syrups) not prescribed for you.
• Don't wear tight underwear or foundation garments. Any skin irritation may trigger new outbreaks.
• Don't take hot baths or showers.
• Apply cold-water compresses or soaks (see Soaks in Appendix) to relieve itching.

MEDICATION--Your doctor may prescribe:

• Antihistamines, ephedrine, terbutaline or cortisone drugs to relieve itching and rash.
• Sedatives or tranquilizers for anxiety.
• Epinephrine by injection for severe symptoms.

ACTIVITY--Decrease activities until several days after hives disappear. Avoid getting hot, sweaty or excited.

DIET--

• If foods are suspected as a cause, keep a food diary to help identify the offending food.
• Avoid alcohol and coffee or other caffeine-containing beverages.

Call Your Doctor If

• The following occurs during an episode of hives: Swollen lips. Shortness of breath or wheezing. A tight or constricted feeling in the throat. This is an emergency!
• New, unexplained symptoms develop. Drugs used in treatment may produce side effects.