Angioedema is the swelling of the deeper layers of the skin, caused by a build-up of fluid.
The symptoms of angioedema can affect any part of the body, but swelling usually affects the:
- eyes
- lips
- genitals
- hands
- feet
Many people with angioedema also have another condition called hives, which is also known as urticaria, welts or nettle rash. This is a raised, red and itchy rash that appears on the skin.
Read more about the symptoms of angioedema.
Why does angioedema happen?
The causes of angioedema depend on the type of condition you have. There are four main types of angioedema:
- allergic angioedema – the swelling is caused by an allergic reaction, such as a reaction to peanuts, and sometimes occurs in combination with anaphylaxis
- idiopathic angioedema – there is no known cause for the symptoms of swelling (although certain factors, such as stress or infection, may trigger the symptoms)
- drug-induced angioedema – the swelling is a side effect of certain medications, most often angiotensin-converting enzyme (ACE) inhibitors
- hereditary angioedema – the swelling is caused by ‘faulty’ genes that are inherited from a person’s parents
Read more about the causes of angioedema.
How common is angioedema?
Angioedema is quite a common condition which affects about 10-20% of people during their life, although some types are more common than others.
Food allergies, the main cause of allergic angioedema, are estimated to affect about 5-8% of children and 1-2% of adults.
It is not clear how common idiopathic angioedema is, as it can be misdiagnosed as allergic angioedema. However, long-lasting (chronic) idiopathic angioedema is estimated to affect 1 in 2,000 people.
Although estimates vary, ACE inhibitors are thought to cause drug-induced angioedema in around 1-5% of people who take them.
Hereditary angioedema is rare, only affecting between 1 in 10,000 and 1 in 50,000 people worldwide.
Diagnosis
Diagnosing angioedema is relatively straightforward. Due to its distinctive appearance, a doctor should be able to recognise it after a physical examination.
Further tests, such as blood tests, may be required to determine the exact type of angioedema.
Idiopathic angioedema is only diagnosed if no cause can be found after testing.
Read more about diagnosing angioedema.
How is angioedema treated?
Although most cases of angioedema get better without treatment after a few days, medication is often used.
For cases of allergic and idiopathic angioedema, antihistamines and oral steroids (steroid tablets) can be used to relieve the swelling.
Drug-induced angioedema can usually be treated by using an alternative medication to treat whatever underlying condition you have.
Although the condition cannot be cured, regular drug treatment can prevent attacks in people with hereditary angioedema.
Read more about treating angioedema.
