Patient Education

Hives and Swelling (Urticaria and Angiodema)

What is hives/angioedema?

Hives (urticaria) are raised, red, itchy areas on the skin (also called wheals or welts) that appear as an allergic skin reaction. There can be one or many hives in any part of the body and they can present with various sizes and shapes. If the hives occur deeper in the skin they can cause swelling (angioedema).

How does hives/angioedema occur?

Most often, no cause for hives or angioedema can be identified. Clusters of hives may appear as an allergic reaction to one or more factors (irritants) such as foods, medications, insect bites or stings, infections, or emotional stress. Histamine, a body chemical, is released in response to the irritant that causes the hives to form. These hives or wheals may appear on any part of the body, but are most common on the arms, legs, and trunk. The rash may last for a few minutes or several days. It may recur and can be uncomfortable. In the case of a severe reaction to a bee sting, for example, your face and throat may swell. Hives may rarely cause problems with breathing.

How is hives/angioedema diagnosed?

We will examine the affected area and will ask about your history of sensitivity to such things as food (commonly eggs, shellfish, milk, nuts, berries, dyes or other additives), drugs (such as penicillin, aspirin, or sulfa), plants or pollens, animal fur, insect bites or stings, or other physical factors (exposure to heat, cold, or sunshine). To determine the cause of your hives, we ask that you keep a detailed diary of everything you eat, drink, take and are exposed to. It is easiest to identify drugs, foods, or plants that may cause you to have hives because the response usually occurs within an hour. Finding what triggers hives such as emotional stress or multiple allergies may take more time and require skin or other tests.

How is hives/angioedema treated?

Treatment depends on how serious your hives are. Simple measures that may help relieve the itching and reduce the swelling include soaking in a lukewarm bath, using cool compresses and avoiding heat or rubbing, which releases more histamines. If the rash is severe and/or not responding to the above treatments, we may prescribe stronger medications to combat the hives. Some allergic reactions are emergencies. If your hives have abrupt onset and are spreading quickly, or if there is any question of throat swelling/tightness or difficult breathing or of wheezing, you should seek medical advice immediately. These severe allergic reactions can be life threatening and require immediate medical attention.

How long will the effects of hives last?

The effects of hives can last from a few hours to several weeks, months or years. Hives will eventually clear without treatment, but taking some medications can help the hives go away faster, treat the itch, and prevent new hive formation. Chronic urticaria last for a longer period and for more than 70% of cases, it is not possible to determine a cause. Antihistamines are usually very helpful. The hives resolve spontaneously after weeks, months or years but may recur.

How can I take care of myself?

Call our office or 911 at once if you have an allergic response that affects your breathing. You should also call if you continue to have outbreaks of hives. In addition, follow these guidelines:

  • If your face begins to swell around your lips or tongue, call your doctor or 911 at once.
  • Take medications as advised by our office to help relieve your symptoms.
  • Avoid foods that seem to cause you to break out.

What can be done to help prevent hives from recurring?

When you know the cause of your hives you should take steps to avoid the offending irritant. You may need to take frequent, even daily, medication to prevent recurrences.

Dr Pulin Patel, Allergy & Asthma Specialist

Have a Question?

Contact our staff by phone or form.