Hereditary Angioedema

Hereditary angioedema (HAE) is a hereditary disease. This disease causes sudden and painful swellings due to fluid accumulation under the skin and mucous membranes. These swellings can occur in the hands, feet, face, intestinal tract, and respiratory tract, negatively affecting the patient’s quality of life.

It can be seen on the face, eyelids, lips, tongue, hands, feet, and genital area. It can also affect the digestive system, causing severe abdominal pain. When it occurs in the respiratory tract, it can pose serious health risks.

Hereditary angioedema is a rare genetic disease characterized by sudden and recurrent swellings in various parts of the body. These swellings typically appear on the hands, feet, face, respiratory tract, digestive system, and even the genital area. Life-threatening severe airway edema can occur. The disease is inherited in an autosomal dominant manner, meaning it can be passed genetically from family members.

Hereditary angioedema symptoms are often as follows:

• Painless but firm swellings under the skin (especially on the hands, feet, and face)
• Gastrointestinal complaints such as abdominal pain, nausea, and vomiting
• Shortness of breath and choking sensation if edema occurs in the respiratory tract
• Swellings that may appear in the genital area
• Acute attacks usually start suddenly and may last for several days
• The frequency of attacks varies from person to person; in some patients, several times a month, in others, several times a year

Angioedema and urticaria can develop due to different causes. If urticaria (hives) is seen along with angioedema, this condition is usually allergic in origin and responds to allergy medications.

However, hereditary angioedema is different from classic allergic angioedema. Urticaria usually does not accompany it and does not respond to allergy medications. Therefore, if there is chronic urticaria, a different diagnosis should be considered.

The main cause of hereditary angioedema is genetic mutations that affect the C1 inhibitor protein. As a result of these mutations, this protein is either not produced at all or cannot function properly. The C1 inhibitor is a protein that plays an important role in the immune system and vascular permeability. Due to the deficiency or insufficiency of this protein, fluid leakage occurs in the body and swellings develop.

Hereditary angioedema is usually suspected based on the patient's history and whether there are similar cases in the family. The following tests are used to confirm the diagnosis:

• C4 level: Usually low.
• C1 esterase inhibitor level: May be deficient or nonfunctional.
• Genetic tests: Identify the specific mutation and help confirm the diagnosis.

Treatment of hereditary angioedema involves both the prevention of attacks and intervention during acute episodes. Therefore, the treatment plan should be tailored to the individual.

Treatment of Acute Attacks
The main medications used during attacks include:

• C1 inhibitor concentrates: Replace the deficient protein.
• Bradykinin receptor antagonists
• Kallikrein inhibitors
• These treatments help rapidly reduce swelling and prevent serious complications.

Preventive Treatment
For individuals with frequent attacks, the following treatments are preferred:

• Regular C1 inhibitor concentrates
• Antifibrinolytic medications
• Monoclonal antibodies
• In addition, hereditary angioedema medications require regular monitoring and dose adjustments.

This condition is generally managed by the departments of Immunology and Allergy Diseases or Internal Medicine. However, depending on the symptoms, Gastroenterology, Ear, Nose and Throat (ENT), or the Emergency Department may also be involved in the process.

As this is a rare condition, the diagnosis and treatment process requires experienced physicians. Hereditary angioedema specialists are experts who understand genetic testing and are knowledgeable about C1 esterase inhibitor deficiency. These doctors can intervene quickly in the event of a crisis.

Yes, hereditary angioedema is a genetic disease. Since it follows an autosomal dominant inheritance pattern, a child of a parent carrying the disease may develop the condition. However, in some cases, it may also occur due to new gene mutations.

No, it is a hereditary disease and not contagious. It can be passed from parents to children genetically.

In hereditary angioedema, swelling attacks typically intensify within 12 to 36 hours. The swelling subsides within 2 to 5 days. This duration may vary from patient to patient. Early intervention and treatment can help reduce the swelling more quickly.

If left untreated, the attacks may last longer and the swelling may become more severe. Medical intervention can shorten the duration of symptoms and improve the patient’s comfort.

If hereditary angioedema is not treated, life-threatening attacks may occur. Angioedema does not respond to allergy medications, and the swelling may persist for up to 5 days. Without treatment, the patient may require intensive care, which can pose a serious threat to life.

Swelling in the airways is particularly dangerous, as it can lead to breathing difficulties and the risk of suffocation. Therefore, early treatment and specialist supervision are extremely important.

Swelling in the airways (laryngeal edema) can cause difficulty breathing and risk of suffocation. Therefore, patients should recognize attacks early and seek emergency medical help.

• Stress and emotional factors
• Infections and illnesses like the flu
• Surgical procedures and dental treatments
• Certain medications (such as ACE inhibitors for blood pressure)
• Hormonal changes (pregnancy, birth control pills, menstrual cycle)

• Avoid triggers
• Follow prophylactic treatment recommended by the doctor
• Keep medications available for emergency situations
• Have knowledge about the disease and inform close contacts