The main sign of angioedema is swelling that develops below the skin’s surface. The swelling is caused by a collection of fluid in the deep layers of the skin. Angioedema is often caused by a problem with the immune system, although there are many cases where no cause can be identified. In
allergic angioedema, your immune system mistakenly attacks harmless substances in your blood. Your body produces the chemical histamine, which causes the blood vessels in the area to expand, leading to swelling of the skin. Substances known to trigger allergic angioedema include: certain types of food – particularly nuts, shellfish, milk and eggs; some types of medication – such as penicillin, aspirin and non-steridal anti-inflannatory drugs (NSAIDs), such as ibuprofen; insect bites and stings – particularly wasp and bee stings and latex – a naturally occurring rubber used to make medical gloves, balloons and condoms. Cases of angioedema without an identifiable cause are known as idiopathic angioedema. It may be that a problem with the immune system sometimes causes it to “misfire”. In cases of idiopathic angioedema, certain triggers may lead to swelling, such as: anxiety or stress, minor infections, hot or cold temperatures and exercise.
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