What is angioedema?
Angioedema is swelling (oedema) caused by a build-up of fluid in deeper layers of the skin.
Angioedema is characterised by deep swelling around the eyes and lips and sometimes of the genitals, hands or feet. The swelling usually goes away within 24-72 hours.
Up to 1 in 5 people experience angioedema during their lives, according to the NHS.
Occasionally severe, prolonged tissue swelling can be disfiguring. Rarely, angioedema of the throat, tongue or lungs can block or restrict the airways, causing difficulty breathing. This may become life threatening.
Seek urgent medical attention by calling 999 for an ambulance if a person has angioedema swelling and they:
If the person is someone at risk of a serious allergic reaction and they carry an adrenaline auto-injector pen, this should be used before emergency medical help arrives.
How does angioedema differ from urticaria?
People with angioedema may also experience a raised, red and itchy rash on the skin's surface, called hives or urticaria. These wheals or rashes usually affect top layers of skin, like a nettle rash. These may occur at the same time as angioedema - or at a different time.
However, angioedema is defined by the effect it has on deeper skin tissue.
Types and causes of angioedema
The main types of angioedema are:
- Allergic angioedema, caused by an allergic reaction or anaphylaxis
- Drug-induced angioedema, caused by side-effects of a medication
- Idiopathic angioedema, with no clear cause and the trigger cannot be determined
- Hereditary angioedema (HAE), caused by inherited ‘faulty’ genes and affects between 1 in 10,000 and 1 in 50,000 people globally.
Allergic angioedema triggers
Angioedema can be triggered by different things in different people, but triggers include:
Other allergic reactions are possible, as well as the body's defence system reacting wrongly to other events, such as:
- Stress, anxiety
- Temperature changes - hot or cold
- Vigorous exercise.
Symptoms of angioedema
Angioedema can affect people in different ways, but symptoms can include:
- Swelling of the hands, feet, eyes, lips, tongue or genitals
- Rash lasting some days
- Breathing problems, restricted airways
- Eyes itching or redness
- Abdominal pain
- Feeling lightheaded or fainting.
An initial diagnosis of angioedema will involve the doctor examining the affected area and talking about the symptoms and possible triggers.
More tests may be arranged to pinpoint the type of angioedema, including allergy tests or blood tests.
If no clear cause is found, the diagnosis may be idiopathic angioedema.