Angioedema is a temporary, recurring subcutaneous or submucosal swelling. It
- gastrointestinal tract
- upper airways
The direct cause of the swelling is leaking blood vessels in the surrounding tissues or skin, but there are several potential underlying causes of the condition.
In some cases, swelling occurs along with the appearance of hives. This is why angioedema is sometimes referred to as “giant hives.”
Hives are itchy and raised welts that develop on the skin’s surface, involving the top two skin layers.
Causes of either angioedema or hives include:
- an allergic reaction or intolerance to food
- a side effect or allergy to a medication
- an allergen in the surrounding environment, such as pollen, pet dander, and venom from insect bites
In other cases, a doctor may not know the underlying cause.
Some areas of the body, such as the eyelids, lips, and tongue, are more prone to angioedema than others.
When angioedema is passed from a parent to a child through genetic transmission, the condition is known as “hereditary angioedema.”
Hereditary angioedema has different causes than acquired angioedema, but the symptoms and treatment approaches are similar.
Angioedema may or may not be accompanied by swelling and welts on the skin’s surface known as urticaria (hives). Allergic angioedema can cause itchiness.
Other angioedema symptoms may include:
- abdominal cramping
- shortness of breath
In more severe cases, people with angioedema may experience swelling of the airways, making it difficult to breathe, and an unsafe drop in blood pressure.
Call 911 or go to an emergency room right away if you’re having trouble breathing. This may be a sign of a medical condition that requires prompt treatment.
Below are descriptions of several potential causes of angioedema.
Allergic angioedema is the
Some potential causes include:
- insect stings
- insect bites
Nonallergic drug-induced angioedema
Drug-induced angioedema is the
A common cause includes angiotensin-converting enzyme inhibitors, a common blood pressure medication.
Hereditary angioedema (HAE)
Hereditary angioedema (HAE) is
Idiopathic angioedema occurs when a doctor cannot find a cause for the angioedema. Idiopathic cases of angioedema may occur in up to 40% of cases. Experts do not know much about how idiopathic angioedema starts or its nature.
Acquired angioedema may also develop after an infection or illness, such as lupus (SLE). In
Certain factors may increase your risk of developing angioedema.
Risk factors can vary based on the severity or cause. Some potential risk factors associated with recurrent and severe angioedema
- being over 65 years old
- being of Hispanic descent
- having ACEi-induced angioedema
- having coexistent cardiopulmonary disease
Another study from 2020 noted that people who take ACE inhibitors might have a higher chance of developing angioedema due to:
- being born female
- being of African American descent
- taking NSAIDs
- living in the upper Midwest
If you have allergies, try to avoid known triggers because these may cause angioedema. Other risk factors may include:
- a previous occurrence of angioedema or hives
- a previous allergic reaction
- a family history of angioedema or hives
- sudden temperature changes
- stress or anxiety
- certain medical conditions
A doctor will perform a physical exam and ask you about your symptoms and medical history. During the exam, your doctor will examine your swelling and welts, if any are present. They may also listen to your breathing to see if your throat has been affected.
Be sure to tell your doctor if you’ve recently been exposed to substances that have triggered an allergic reaction. This information may help them determine the specific cause of your reaction.
Your doctor will perform blood tests if hereditary or acquired angioedema is suspected. These
- C1 esterase inhibitor testing
- checking levels of complement components, including C2 and C4
These tests measure the levels or function of certain proteins in the blood. Abnormal results can be associated with a health problem related to an underlying autoimmune disease. They can also help determine the best course of treatment.
- epinephrine (EpiPen) if due to an acute allergic reaction
- antihistamines such as loratadine and cetirizine if due to an allergic reaction or angioedema when the cause is unknown
- glucocorticosteroid such as prednisone or Solu-Medrol if due to an acute allergic reaction
Hereditary angioedema may require surgical intervention or intubation. They may also treat a person with:
- C1 inhibitor concentrate
- ecallantide (Kallikrein inhibitor)
- icatibant (bradykinin-receptor antagonist)
If possible, avoid contact with substances that may cause swelling. In less severe cases of angioedema, the following home remedies may help:
- applying cool, wet compresses to soothe the skin and prevent scratching
- wearing loose cotton clothing to avoid further skin irritation
If a medication is causing you to have angioedema, your doctor may have you switch to a different one.
If you are pregnant, you should talk with your doctor before starting any medication or before treatment.
Long-term treatment for recurrent angioedema
In many cases, angioedema is a harmless condition that will disappear within
However, angioedema can be dangerous when severe swelling occurs near the throat. A swollen throat or tongue can block your airway and make breathing difficult.
Severe angioedema may be due to anaphylaxis, a life threatening, severe acute allergic reaction. In such severe cases, you should seek emergency medical help immediately.
The best way to prevent allergic angioedema is to avoid known and suspected allergens or those that have caused the condition to occur previously.
Taking these preventive measures can help lower your risk of having another episode.
Angioedema is swelling that occurs deep within the skin or around mucous membranes. It is often due to allergens or reactions to medications, though the cause may also be unknown. Symptoms can range from mild to life threatening, so you may need emergency medical care, especially if you have trouble breathing.
When treatment is needed, doctors will often recommend antihistamines or other medications to help the swelling go down. Mild cases may not need treatment and can clear within a few days.