Angioedema is a sudden, severe swelling of the skin in a particular area. This skin reaction commonly affects the:
- eyes,
- lips,
- nose,
- tongue,
- voice box (larynx),
- hands, or
- bowel.
Why does it happen?
Some types of angioedema are idiopathic. This means there is no known reason why a person gets it.
One in 50,000 people inherit the genes for this condition from their parents (called inherited angioedema).
The swelling happens because too much fluid collects in the deep layers of skin tissue. The top layer of skin may look normal. Angioedema can continue for hours or even days.
Angioedema often happens at the same time as hives (nettle rash), which are itchy swellings on the surface of the skin.
How is it triggered?
Some cases of angioedema can be caused by an allergic reaction, for example, a reaction to an insect sting, or by contact with certain foods, plants, drugs or pollens. This is called acute allergic angioedema.
Angioedema can also be triggered by stress, infections, liver and thyroid problems, and certain vitamin or mineral deficiencies.
Attacks in people with inherited angioedema can be brought on by stress or minor operations such as dental surgery. See the Causes page, above, for more information on the different types of angioedema and how they are triggered.
Swelling
Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.
Tissue
Body tissue is made up of groups of cells that perform a specific job, such as protecting the body against infection, producing movement or storing fat.
Genes
Genes contain information that you inherit from your parents, such as eye or hair colour. They are carried by chromosomes.
Acute
Acute means occurring suddenly or over a short period of time.
Allergic
An allergen is a substance that reacts with the body's immune system and causes an allergic reaction.
