Hereditary Angioedema
What is Hereditary Angioedema (HAE)?
Hereditary Angioedema (HAE) is an inherited condition that affects a person's ability to process proper amounts of a certain protein called C1-esterase inhibitor (C1-INH). People with HAE experience recurrent episodes of swelling in the face, extremities, genitals, bowel wall, and airway, causing serious and sometimes life-threatening complications.
The severity and frequency of the episodes of swelling can vary greatly from case to case. For some people, episodes may be few and far between; for others, they may be more frequent and severe. As such, some people may need medication to control their symptoms.
Types of Hereditary Angioedema
HAE is divided into three types: Type I, II, and III. Each type is caused by a different genetic mutation.
Type I: This is the most common type of HAE, and is caused by a mutation in the SERPING1 gene. It's characterized by a deficiency in the production of C1-INH, which helps regulate various biological processes.
Type II: This type of HAE is caused by mutations in the F12 gene. It's characterized by a lack of functional C1-INH that's produced in the body.
Type III: This type of HAE is caused by mutations in theNOD2 gene. It's also characterized by a lack of functional C1-INH.
Symptoms of Hereditary Angioedema
The hallmark symptom of Hereditary Angioedema is episodes of swelling in various areas of the body. The swellings tend to occur on the face, trunk, upper and lower extremities, genitals, and bowel wall. In some cases, the airway may also be affected. Common symptoms include:
- Sudden, intense swelling of the face, lips, hands, feet, or other parts of the body
- Redness or hives on the skin with the swelling
- Severe abdominal pain, vomiting, and diarrhea
- Hoarseness or difficulty breathing
- Lightheadedness or fainting due to low blood pressure
Diagnosis of Hereditary Angioedema
HAE is typically diagnosed using a combination of physical examination, medical history, and laboratory tests. Imaging tests like diagnostic ultrasound and computed tomography (CT) may be used to help rule out other conditions with similar symptoms, such as an allergic reaction. Blood tests are also used to measure the levels of C1-INH and other proteins.
Treatment of Hereditary Angioedema
There is no cure for Hereditary Angioedema; however, treatment is available to reduce the severity and frequency of symptoms. Treatment options include:
- Replacement therapy: In this type of therapy, C1-INH protein is replaced with a synthetic or natural version. This is used to treat acute attacks and prevent future episodes.
- Oral medications: Certain oral medications can help prevent episodes of swelling, though they may not be successful in treating already-developed symptoms.
- Supportive care: This may include the use of antihistamines, anti-inflammatory medications, and other medications to reduce the swelling and alleviate pain.
- Surgery: In some cases, surgery may be necessary to remove damaged tissues and help prevent blockage of the airway.
The main focus of treatment is to reduce the severity and frequency of HAE attacks. Treatment is usually tailored to each individual's specific case and may change over time as the condition progresses.