Angioedema: Causes, symptoms, diagnosis, treatment and prevention

Angioedema is the rapid onset of skin swelling and redness that is similar to hives to some extent. Angioedema tends to cause swelling in the deeper layers of your skin, often in the face, particularly the lips. In most cases, it is an allergic reaction to allergens. However, in some cases, angioedema could be hereditary.


In the majority of cases, angioedema is caused by an allergic reaction. The allergens can be medications, foods, environmental factors, etc. Common allergens that could cause an angioedema include: pollen, poison ivy, latex, animal dander, angiotensin-converting enzyme inhibitors (such as lisinopril), shellfish, peanut, etc.

Some people have angioedema due to a hereditary deficiency of C1 esterase inhibitor, which functions to inhibit C1 esterase. The C1 esterase works to dilate the blood vessels and makes them more permeable so that the blood fluid can leak into the surrounding soft tissue. In normal healthy individuals, the C1 esterase inhibitor works to inhibit the function of C1 esterase and thus prevents the blood vessel dilation. Patients with hereditary C1 esterase deficiency tend to have angioedema upon stimulus, such as pregnancy, contraceptive use, infections, skin scratching or a minor trauma.


Regardless whether the angioedema is acquired or hereditary, their clinical symptoms are similar. The main symptom is sudden appearance of tissue or skin swelling. In some patients, this is associated with skin itching, mild pain or skin warmth. In rare cases, it may even lead to anaphylactic shock. The swelling can appear in any body parts, but they are more common in exposed areas, such as your face.


It is not hard to diagnose angioedema with characteristic symptoms. After confirming angioedema, your doctor would proceed to look for underlying allergens for your condition by asking about your medical history and reviewing your drug chart. Your doctor may also order allergen test to look for allergens that you are allergic to.

If hereditary angioedema is suspected, blood tests to measure C4, antigenic C1 inhibitor, functional C1 inhibitor and C1q would be performed.


For acquired angioedema, the most important treatment is to avoid the allergens as much as you can. Once the angioedema occurs, medications such as cetirizine would be prescribed to control the itching. Topical hydrocortisone may also be used to reduce tissue swelling. If your angioedema is caused by drugs, your doctor may need to discontinue or switch the medications.

For hereditary angioedema, medications like kalbitor (ecallantide), or firazyr (icatibant) may be very useful for treating acute attacks.

Anaphylactic shock caused by angioedema is a medical emergency that requires urgent treatment, such as using epinephrine and/or intubation.


The following are some ways to help preventing repeated angioedema attacks:

  1. Avoid triggers for your angioedema. It’s the most important and effective way of prevention.
  2. Talk to your Obstetrician about this condition if you are pregnant to ensure an uneventful delivery.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.