Angioedema is the rapid edema, or swelling, of the area beneath the skin or mucosa. It is normally caused by an allergic reaction, but it may also be hereditary.

Angioedema affects approximately 10-20% of people. It happens when part of a person’s body becomes swollen, and it tends to affect loose areas of tissue, including:

  • the face, such as the eyelids, mouth, and tongue
  • the limbs, such as hands or feet
  • the genitals

The swelling happens beneath the skin when fluid accumulates, sometimes similar to hives (urticaria).

However, while urticaria only affects the top layer of skin, angioedema affects the deeper layers, such as:

  • subcutaneous tissue
  • the mucosa
  • submucosal tissues

It is not uncommon to have both urticaria and angioedema at the same time.

Angioedema can be fatal, being associated with 5,768 deaths between 1979 and 2010.

When to get medical help

In some cases, angioedema may cause swelling of the throat and airways.

Although the condition is normally mild, if it progresses rapidly, or if it affects the throat, it can cause asphyxiation. This will lead to the following signs/symptoms:

  • sudden or rapidly escalating breathing problems
  • noisy breathing
  • dizziness
  • collapsing

This is a medical emergency. Contact an emergency medical professional immediately if you notice these signs.

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There are four main kinds of angioedema.

Allergic angioedema

This is the most common type. It usually affects those with an allergy to certain types of:

  • food
  • medication
  • venom
  • pollen
  • animal dander

In serious cases, a person may experience a severe allergic reaction known as anaphylaxis. Their throat may swell, making it hard to breathe, and their blood pressure may fall suddenly. This is a medical emergency.

This type of angioedema is not chronic. As soon as the individual identifies what is causing the allergic reaction, they can avoid it.

Drug-induced angioedema

Certain medications may cause angioedema. Examples include:

ACE inhibitors are responsible for up to 30% of emergency room visits linked to angioedema.

If angioedema stems from using an ACE inhibitor, a doctor may prescribe a different type of medication.

Hereditary angioedema

Angioedema may be inherited from family members.

Hereditary angioedema is rare, only affecting roughly 6,000 people in the United States.

The condition typically involves a person having dysfunctional C1 esterase inhibitor (C1-INH) protein or having low blood levels of properly functioning C1-1NH protein.

For hereditary angioedema, symptoms may come and go over time.

Idiopathic angioedema

If a disease is idiopathic, the cause is unclear. For this type of angioedema, the doctor may not be able to identify a specific cause for angioedema after checking for typical causes.

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Symptoms of angioedema typically appear suddenly and may remain for up to 3 days.

Swelling beneath the skin’s surface is the most common symptom of angioedema and may affect a person’s:

  • hands
  • genitals
  • feet
  • legs
  • eyes
  • throat
  • tongue
  • bowel lining

Other symptoms may include:

  • a hot, prickling, or painful sensation
  • an itchy, red rash (urticaria)
  • impaired vision
  • abdominal pain
  • bladder problems
  • difficulty breathing

In severe cases, anaphylactic shock may occur, which can be life threatening.

Emergency medical treatment is required if a person:

  • suddenly develops symptoms of angioedema like an allergic reaction
  • has breathing problems that are sudden or worsening
  • feels faint or dizzy or collapses

If the person knows they have an allergy, they may have an autoinjector, such as an EpiPen. They can use this while waiting for medical help.

The cause of angioedema depends on its type.

Type of angioedemaCauses
Allergic angioedema• insect, snake, or animal bites
• contact with latex
• medications such as penicillin or aspirin
• eating certain foods
Drug-induced angioedema• ACE inhibitors
Hereditary angioedema• gene that causes dysfunctional or low C1-1NH protein blood levels

Other triggers may include:

  • pregnancy
  • contraceptive pills
  • infection
  • trauma

In some cases, the cause may not be identified.

A doctor may diagnose angioedema based on:

  • appearance of symptoms
  • a description of what may have triggered symptoms
  • requesting and reviewing a person’s family, medication, and medical history

If a person was exposed to a common allergen before angioedema occurred, allergic angioedema is likely. Alternatively, a family history of angioedema may suggest that angioedema presenting is hereditary.

A doctor may refer a person with angioedema for further testing to confirm the type. Tests may include:

  • a skin prick test in which the skin is pricked with a very small amount of the suspected allergen
  • a blood test to see how the immune system reacts to a certain allergen
  • a blood test to check for C1 esterase inhibitors, where low levels or dysfunction suggests the problem is hereditary

Treatment for angioedema depends on the type and cause, although most cases improve after a few days without treatment.

Identifying and avoiding an allergen that may have caused angioedema is key to preventing further symptoms.

If intervention is required, medications prescribed may include:

  • antihistamines
  • corticosteroids
  • epinephrine (EpiPen)

If the cause is hereditary, there is no cure. However, a person may receive several types of treatment to help prevent angioedema symptoms, such as receiving:

  • specialized medications
  • a concentrate of the C1 inhibitor
  • the protein they are missing
  • fresh frozen plasma

If a person experiences sudden swelling or trouble breathing, urgent medical attention is required. The most important action is to ensure a free airway, so a breathing tube might be placed for safety.

The most serious complication of angioedema is swelling of the throat and airways, which may cause an inability to get adequate oxygen into the airways.

This is an emergency, and immediate medical attention is required.

What is the most common cause of angioedema?

Angioedema is most commonly caused by an allergen, such as certain foods, medications, or environmental factors.

How serious is angioedema?

Most cases of angioedema go away on their own without treatment.

However, severe angioedema of the throat and tongue can cause trouble breathing, which can be life threatening. This is an emergency and requires immediate medical attention.

How do you fix angioedema?

Treatment depends on the type of angioedema a person is experiencing. Many cases will go away on their own without treatment after a few days.

If symptoms do not go away, a doctor may prescribe medications to help treat angioedema.

Angioedema is when swelling occurs on someone’s body beneath the skin. Symptoms typically last up to 3 days and go away on their own without treatment.

However, in some cases, a person may need further intervention, which may include medications.

If a person is experiencing trouble breathing or anaphylaxis, immediate medical attention is required.