Types of Angioedema

Acute allergic angioedema is the most common type of angioedema that occurs because of an allergic reaction. In this type of angioedema, the body mistakenly identifies certain harmless external substances, such as food or medications, as harmful. It then releases certain chemicals to attack these external substances. These chemical reactions in the body lead to angioedema and cause the skin to swell.

Acquired angioedema is a rare type of angioedema that’s commonly associated with an underlying illness, such as cancer or an autoimmune disease. Like other types of angioedema, acquired angioedema is characterized by swelling attacks that can occur anywhere in the body. Swelling in this type of angioedema is caused by a C1-INH deficiency.

Hereditary angioedema is inherited and occurs due to genetic abnormalities that cause a deficiency in the levels of C1 protein. It is a chronic disease characterized by sudden but temporary swelling in the deeper layers of the skin that usually appears on its own, without hives or a rash. Hereditary angioedema is divided into three subtypes.

Idiopathic angioedema is a broad class of angioedema given to cases of an unknown cause. It consists of a type of swelling that can occur anywhere on the body, but most frequently appears around the lips and eyes. This type is often chronic, relapsing, and mostly accompanied by hives or urticaria. 

Nonallergic angioedema is a type of angioedema that occurs due to an adverse reaction to certain medications. Like other types of angioedema, it is marked by swelling. Angiotensin converting enzyme (ACE) inhibitors, which are commonly used to treat high blood pressure, are the most notable class of medicines that can trigger nonallergic angioedema.