Angioedema (Giant Hives)

Written by Elly Dock and Winnie Yu | Published on July 25, 2012
Medically Reviewed by George Krucik, MD


Angioedema is severe swelling beneath the skin. The swelling may also occur on the surface of the skin. In some cases, the swelling is combined with the appearance of hives. Some areas of the body such as the face and limbs, are more prone to swelling than others. It’s due to this swelling that angioedema is sometimes referred to as “giant hives.”

When angioedema show up in a family, the condition is known as hereditary angioedema. Hereditary angioedema has different causes, symptoms, treatments, and complications than regular angioedema.

What Causes Angioedema?

Doctors believe that angioedema may be the result of an adverse allergic reaction. For this reason, the causes of angioedema may be classified as allergens, which will vary from person to person.

Many people diagnosed with angiodema never discover the cause. The following factors may cause angioedema:

  • insect bites
  • pollen
  • animal dander
  • medication
  • different types of foods
  • exposure to heat, cold, or sunlight

Who Is at Risk for Angioedema?

Angioedema may occur in combination with illnesses and autoimmune disorders. It may also occur after you recover from an infection. Hereditary angioedema occurs in people with a family history of the condition. Individuals with hereditary angiodema may have abnormal function or low levels of a protein called C1 inhibitor.

What are the Symptoms of Angioedema?

Angioedema may or may not appear with swelling and welts on the surface of the skin. The most common symptom is swelling beneath the surface of the skin. Swelling may occur on the feet, throat, hands, eyes, and lips. It may spread throughout the body or appear in a line on the affected area.

Additional symptoms of angioedema may include:

  • swollen eyes or lining of the eyes
  • swollen mouth
  • abdominal cramping
  • difficulty in breathing

Hereditary angioedema causes slightly different symptoms. These symptoms include:

  • swelling of the intestinal tract
  • swelling in the eyes, tongue, lips, throat, arms, or legs
  • abdominal cramping
  • airway blockage

How is Angiodema Diagnosed?

Your doctor will examine your skin to see if you have angioedema. Your doctor may ask if you have been exposed to substances that irritate your skin. During a physical exam, the doctor may listen to your breathing. If your throat has been affected, the physical may reveal abnormal breathing sounds.

If your doctor suspects hereditary angioedema, you may undergo a series of blood tests. Ideally, these tests are performed while you are experiencing an angioedema episode. Blood tests may include:

  • C1 inhibitor level and function
  • complement components C2 and C4

How Is Angioedema Treated?

Individuals with mild symptoms of angioedema may not need treatment. If symptoms are moderate or severe, treatment may require medications such as:

  • epinephrine
  • antihistamines
  • ranitidine
  • anti-inflammatory medications
  • terbutaline

If you are experiencing any difficulty breathing, it is an emergency. You should get medical help immediately. Individuals who are diagnosed with hereditary angioedema may be treated with a C1 inhibitor concentrate and other medications. If an individual has experienced an episode of hereditary angioedema, the doctor may prescribe fluids and pain relief medications via intravenous (IV) injection.

What Is the Long-Term Outlook?

When angioedema does not obstruct your airway, it may disappear within days. This type of angioedema is generally harmless. If swelling near the throat occurs however, the condition can be dangerous. Individuals may experience anaphylaxis or repeated airway blockages.

Hereditary angioedema, on the other hand, can be life threatening. The treatment options for this condition are minimal. Recovery may vary and will depend on the severity of symptoms.

How Do I Prevent Angiodema?

Although there is no way to prevent angioedema, you may be able to lower the odds of a recurrence in the future. Avoid known allergens. Try not to irritate areas on the body that have been previously affected.

Unfortunately, there is no known way to prevent hereditary angiodema. However, genetic counseling may be helpful for people considering a family.

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