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What is Angioedema: Causes, Symptoms, Types, Treatment, Who is at Risk, Diagnosis

What is Angioedema and What Are Its Causes?

Angioedema is a type of swelling that occurs in the deeper part of your skin’s inner layer and in the layer below that. It may go on to become a severe condition if it’s not treated.(1)

In some cases, this inflammation happens along with the appearance of hives as well. Due to this reason, angioedema is sometimes also referred to as giant hives.

Hives are raised, red welts that develop on the skin’s surface and involves only the two skin layers. Hives is also known as urticaria.(2)

What is Angioedema and What Are Its Causes?

Both hives and angioedema can be caused by the following:

  • An allergic reaction to food or food intolerance
  • A side effect of a medicine
  • Allergic reaction to a medication such as penicillin or aspirin
  • Certain medication, especially such as angiotension-converting enzyme (ACE) inhibitors, can cause drug induced angioedema
  • Environmental allergens such as pet dander, pollen, contact with latex, and venom from insect bites
  • Other causes or triggers for angioedema can also include contraceptive pills, pregnancy, infection, or trauma.

In some extremely rare cases, the ensuing swelling can also be a sign of a more serious underlying health condition, such as non-Hodgkin B-cell lymphoma. Some parts of the body, including the lips, eyelids, and tongue, are more likely to be affected by angioedema than others.

Angioedema is also passed on from a parent to a child through genetic transmission. This condition is known as hereditary angioedema.(3)

The causes of hereditary angioedema are different than acquired angioedema, but in both cases, the symptoms and treatment approaches will be similar.

Angioedema can also be a part of another serious medical condition.

When angioedema is caused by an acute allergic reaction, and when the condition is properly treated, the chances of complete recovery from the condition are extremely favorable. If you have mild angioedema, then it is likely to resolve on its own without needing any treatment.

Symptoms of Angioedema

The most commonly observed symptom of angioedema is swelling with a red-colored rash that appears just underneath the surface of your skin. It usually appears in a localized area such as on or near the feet, eyes, hands, or lips.

In the more severe cases of angioedema, the inflammation tends to spread to other parts of the body. Angioedema is such a condition that it may or may not be accompanied by the welts and swelling on the skin’s surface, making it difficult to be diagnosed.(4)

The swelling that is caused by angioedema deep inside the skin is known to affect a person’s hands, feet, genitals, the face, and the lining of the bowel and throat. The signs and symptoms of the disease appear suddenly and rapidly and can remain for up to 3 or more days. If hives also develop along with angioedema, then the skin will become itchy.

In some cases, the swollen parts of the body will feel hot to touch and might also be painful. Some people also find that their vision gets affected.

Bronchospasm occurs in some people if the disease affects the lining of the airways and throat. This could also cause some breathing problems.

In severe cases of angioedema, anaphylactic shock may occur, which is a life-threatening situation, and you must seek immediate medical help.(5)

You might need emergency medical assistance if you notice the following signs and symptoms:

  1. If you suddenly develop symptoms of angioedema, similar to an allergic reaction
  2. If you suddenly start having breathing problems or you find your breathing problems getting worse
  3. If you feel dizzy or faint, or if you faint or collapse

If you are already aware that you have an allergy, then you should keep an autoinjector such as an EpiPen handy with you. You can use this while you are waiting for medical help to arrive.

Different Types of Angioedema

There are four major types of angioedema. These are:

  • Allergic
  • Idiopathic
  • Drug-induced
  • Hereditary

Let’s take a look at each of these kinds.

Allergic Angioedema

Allergic angioedema is the most common type, and it typically affects those who are allergic to a particular food, any medication, pollen, venom, latex, or animal dander. In serious cases of allergic angioedema, there could be a severe allergic reaction known as anaphylaxis. In this condition, the throat may swell up, making it difficult for the patient to breathe. Blood pressure also tends to drop suddenly. This should be considered a medical emergency, and you need to get urgent help.

Allergic angioedema is not a long-term or chronic condition, and as soon as the trigger causing the allergic reaction is identified, the condition can be avoided in the future.

Drug-induced Angioedema

There are some medications also that cause angioedema. These typically include angiotensin-converting enzyme (ACE) inhibitors, which are used in the treatment of high blood pressure or hypertension.

According to the Merck Manuals, nearly 30 percent of angioedema cases that come to the emergency department due to the use of ACE inhibitors.(6)

If you have angioedema caused by using an ACE inhibitor, then your doctor is going to prescribe another type of drug for controlling your blood pressure.

NSAIDs (non-steroidal anti-inflammatory drugs) are also known to cause drug-induced angioedema. These include common painkillers like aspirin or ibuprofen.

Idiopathic Angioedema

The cause of idiopathic angioedema is unclear. If you have idiopathic angioedema, your doctor might not be able to identify the exact cause of what is causing your condition, even after looking at all the usual reasons.

Hereditary Angioedema

Certain types of angioedema can be inherited, meaning that many people in the family might be having the condition. If you have hereditary angioedema, it means that there is an issue with the C1 inhibitor protein in your body. You are likely to have low levels of the protein C1-esterase inhibitor (C1-1NH protein) in your bloodstream.

In hereditary angioedema, the disease episodes tend to come and go.

Who is at Risk for Developing Angioedema?

There are many factors that increase the risk of developing angioedema. These can include:

  • Having a previous allergic reaction
  • Having a prior episode of hives or angioedema
  • Having a family history of hives or angioedema
  • Sudden temperature changes
  • High levels of stress or anxiety
  • Certain medical conditions

Diagnosis of Angioedema

In order to diagnose angioedema, your doctor is going to perform a physical exam and also enquire about your symptoms and previous medical history. During this physical exam, your doctor is going to examine the parts of the body where you have swelling and welts if you have any. They will also monitor your breathing and look at your throat to determine if it has been affected.

It is essential that you let your doctor know about any recent exposure to any substances that you know have previously triggered an allergic reaction in you. This helps your doctor understand and determine the exact cause of your angioedema.

After this, your doctor is likely to order a series of blood tests if they suspect that you might be having acquired or hereditary angioedema. These blood tests may include:

  • C1 esterase inhibitor test
  • Test to look at the levels of complement components such as C2 and C4

These blood tests measure the functioning of certain proteins in the bloodstream. Getting back an abnormal test result is typically associated with having a health problem that is likely to be related to an underlying autoimmune condition.

Treatment of Angioedema

People who have mild angioedema do not need any treatment, and the condition clears up on its own. However, people with moderate to severe symptoms require medications that help in relieving the intense swelling caused by angioedema. These medications include:

  • Antihistamines such as cetirizine (brand name: Zyrtec) and loratadine (brand name: Claritin), if the cause of angioedema is unknown, or if it is a result of an allergic reaction.
  • Epinephrine if the cause is an acute allergic reaction
  • Glucocorticosteroid such as Solu-Medrol or prednisone, if the reason is an acute allergic reaction

Treatment options for acquired or hereditary angioedema are different and typically include:

  • Icatibant
  • Ecallantide
  • Fresh frozen plasma
  • Purified human C1 esterase inhibitor

There are also some home remedies that are known to provide relief in the symptoms of angioedema. These include:

  • Wearing loose cotton clothing to avoid irritating the skin further
  • Applying cold, wet compress to soothe the skin and prevent itchiness

If you have developed angioedema due to a particular medication, then your doctor is going to stop the suspected medication and switch you to another option.


In many cases, angioedema is only a harmless condition that happens as a result of an allergic reaction. It will typically disappear on its own within a couple of days.

However, the condition of angioedema can prove to be dangerous is the swelling is severe and occurs in the airways or the throat. A swollen tongue or throat can end up blocking your airway, making it difficult to breathe. This can lead to anaphylaxis, which is a life-threatening condition, and you need to seek emergency medical attention at the earliest.

It is possible to prevent angioedema and hives, and the best way to do this is by avoiding any known or suspected allergens. You should definitely avoid any known triggers that have caused angioedema in the past. By following these measures, you will be able to lower your risk of having another episode of angioedema.


  1. Nhsinform.scot. (2019). Angioedema symptoms and treatments. [online] Available at: https://www.nhsinform.scot/illnesses-and-conditions/skin-hair-and-nails/angioedema [Accessed 2 Sep. 2019].
  2. Kaplan, A.P., 2002. Chronic urticaria and angioedema. New England Journal of Medicine, 346(3), pp.175-179.
  3. Zuraw, B.L., 2008. Hereditary angioedema. New England Journal of Medicine, 359(10), pp.1027-1036.
  4. nhs.uk. (2019). Angioedema – Symptoms. [online] Available at: https://www.nhs.uk/conditions/angioedema/symptoms/ [Accessed 2 Sep. 2019].
  5. Derangedphysiology.com. (2019). Anaphylaxis and angioedema | Deranged Physiology. [online] Available at: https://derangedphysiology.com/main/required-reading/cardiac-arrest-and-resuscitation/Chapter%201.2.1/anaphylaxis-and-angioedema [Accessed 2 Sep. 2019].
  6. MSD Manual Professional Edition. (2019). Angioedema – Immunology; Allergic Disorders – MSD Manual Professional Edition. [online] Available at: http://www.merckmanuals.com/professional/immunology-allergic-disorders/allergic,-autoimmune,-and-other-hypersensitivity-disorders/angioedema [Accessed 2 Sep. 2019].

Also Read:

Sheetal DeCaria, M.D.
Sheetal DeCaria, M.D.
Written, Edited or Reviewed By: Sheetal DeCaria, M.D. This article does not provide medical advice. See disclaimer
Last Modified On:April 17, 2023

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