Hereditary angioedema (HAE) is a rare disorder caused by a genetic mutation involving the C1 inhibitor (C1-INH) gene. HAE is characterized by recurrent episodes of sudden swelling, called angioedema, that can affect any area of the body. It typically presents as swelling in areas such as the extremities, face, abdomen, or throat that can cause airway obstruction and potentially be life-threatening.

The exact prevalence of HAE is unknown, but it is estimated to affect 1 in 10,000 to 1 in 50,000 individuals. HAE is classified into three types: Type I, II, and III, based on the activity levels of C1-INH proteins in the blood. The most common type is Type I, which is caused by a deficiency of C1-INH proteins. Type II is due to an abnormality in the protein structure, and type III is thought to be caused by an autoimmune dysfunction.

The symptoms of HAE can vary in severity and duration but usually include episodes of swelling that occur without warning and last anywhere from a few hours to a few days. Swelling typically involves the hands, feet, face, and/or abdomen. In severe cases, swelling can also affect the airway, which can lead to difficulty breathing or choking. Along with the swelling, other symptoms may include abdominal pain, nausea, vomiting, and hives.

Treatment for HAE focuses on preventing and managing the swelling episodes. This can include the use of supportive medications such as antihistamines and corticosteroids, or long-term preventative medications that help to increase levels of C1-INH in the blood. For some cases, drugs such as C1-INH replacement therapy or enzyme inhibitors may also be considered. Surgery may be necessary in some cases to remove damaged tissue that cannot be restored through medical management alone.

HAE is a serious and chronic condition that can cause a great deal of disruption and distress to those affected by it. Therefore, it is important for those who are diagnosed with HAE to be under the care of a multidisciplinary healthcare team, including a doctor or specialist, to ensure proper diagnosis and management. With the right care, those with HAE can lead normal, healthy lives with minimal disruption.