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What Are Hives?

The medical term for hives is urticaria, also called wheals (bumps). Swollen, small, pale red bumps or larger patches suddenly appear on the skin. Severe itching usually follows. Each bump tends to go away in 24 hours without leaving marks, but then others appear. They can be very small to large. Scratching can cause the affected skin area to get larger, leading to big, fiery red patches. Hives usually don’t last long. When they last more than 6 weeks, they’re called chronic; when they last less than 6 weeks, they’re called acute.

What Causes Hives?

Hives can be allergic or nonallergic, but often the cause remains unknown. Allergic hives, the least common, are triggered by an overreaction of the immune system to certain things, most commonly foods (nuts, shellfish), insect stings and bites, and drugs (e.g., penicillin).

Causes of nonallergic hives include cold (after exposure to cold weather) and heat (after exercise, hot shower, or stress).

What Are the Symptoms of Hives?

Symptoms include itching, or less often burning or stinging; raised, often red, swellings; and separate swellings that usually go away in 24 hours, but new ones often appear as the old ones disappear.

How Are Hives Diagnosed?

The health care provider will ask about symptoms: when they appeared, how long they lasted, what things may have triggered them. If the health care provider thinks that an allergy is the cause, seeing a specialist in allergies may be suggested. A diary of foods eaten, drugs taken, illnesses, work and home life, and when symptoms appear should be kept.

No specific tests are used for these conditions, so the choice of tests depends on answers to questions about symptoms and a full physical examination. Sometimes, blood and urine tests and skin testing may be done.

How Are Hives Treated?

Antihistamines (like those taken for hay fever) are the most common treatment. In complicated or severe cases, drugs called corticosteroids (prednisone) may be prescribed for a short time.

DOs and DON’Ts in Managing Hives:

  • DO avoid anything your health care provider says will trigger your condition.
  • DO take your prescribed drugs and follow directions for their use.
  • DO avoid stress. This can make your symptoms worse.
  • DO call your health care provider if you have shortness of breath or wheezing.
  • DO call your health care provider if you develop a swollen tongue, lips, or face.
  • DON’T wear tight-fitting clothes that can rub your skin.
  • DON’T towel yourself vigorously after a bath or shower, because this can increase the area of skin affected.
  • DON’T scratch, because this can make the hives worse.
  • DON’T drink alcohol or eat spicy foods. These can make your condition worse.
  • DON’T use harsh soaps or wash too much. Dry skin can cause more itching.

Contact the following sources:

  • American Academy of Allergy, Asthma & Immunology
    Tel: (800) 822-2762
  • American Academy of Dermatology
    Tel: (866) 503-7546


Ferri’s Netter Patient Advisor