Angioedema is a type of swelling caused by large welts deep in your skin. Angioedema usually appears near your eyes and lips. Angioedema is similar to hives but the swelling is beneath the skin rather than on the surface. Angioedema can be present with or without hives.
The main symptom is the sudden development of swelling. Angioedema may also be found on the hands, feet and throat. They may form a line or be more spread out. The welts are painful, itchy, turn pale and swell if irritated. Other symptoms may include abdominal cramping, breathing difficulty, swollen eyes and mouth and swollen lining of the eyes (chemosis).
Angioedema is caused by inflammation in the skin. In some cases angioedema is triggered when certain cells (mast cells) release histamine and other chemicals into your bloodstream and skin. Allergic reactions to medications or foods can cause acute angioedema. Many allergens have been identified. These allergens include food, medications and other substances.
Many foods can cause problems in sensitive people, but shellfish, fish, nuts, eggs, chocolate and milk are frequent offenders. Food additives, such as salicylates and sulfites, are other potential allergens.
Almost any medication may cause angioedema; common culprits include penicillin, aspirin, ibuprofen (Advil, Motrin, others) and blood pressure medications.
Other substances that can cause angioedema include direct contact with pollen, animal dander, latex and insect stings.
Additional triggers that may produce angioedema include environmental factors and dermatographia.
Environmental factors can result in the release of histamine with subsequent angioedema in some people. Examples of these factors include heat, cold, sunlight, water, pressure on the skin, emotional stress and exercise.
Dermatographia is a condition which literally means "write on the skin." When pressure is applied to the skin or the skin is scratched, raised lines appear on those areas due to histamine-based angioedema that leads to swelling beneath the skin.
In addition to these triggers, angioedema sometimes occur in response to your body's production of antibodies.