Angioedema
What are the different types of angioedema? Learn all about its causes, symptoms, and treatments.
Symptoms and Causes
Angioedema is a vascular reaction that causes swelling in the deep subcutaneous layers, usually as a result of an allergic reaction or hereditary factors. It can occur on its own, alongside urticaria, or as part of anaphylaxis (a severe allergic reaction). Unlike urticaria, which affects the superficial layer, it does not cause hives, scabs, or itching, though it is more severe.
There are two types of angioedema based on its origin:
- Hereditary angioedema: Genetically transmitted:
- Type 1 angioedema: The most common type. It involves a deficiency of the C1 inhibitor, which regulates this protein that contributes to the immune system.
- Type 2 angioedema: The C1 inhibitor functions incorrectly.
- Type 3 angioedema: Very rare. The C1 inhibitor functions normally and has normal levels, but there is a genetic mutation in certain factors.
- Acquired angioedema: Uncommon. Certain diseases (lymphoma, lupus, dermatomyositis) cause a deficiency of the C1 inhibitor.
Based on its progression, it is classified as:
- Acute angioedema: Appears suddenly after exposure to a triggering factor.
- Chronic angioedema: Initial symptoms disappear but recur after several months.
The prognosis is positive and usually does not leave lasting effects. However, if the tongue or throat swells, it can be life-threatening.
Symptoms
Angioedema presents the following symptoms:
- Localized swelling. It is most common on the face (facial angioedema), lips (lip angioedema), throat, tongue, genitals, feet, and hands.
- Burning or numbness in the affected area.
- Mild pain.
- Nausea and vomiting if it affects the digestive system.
- Occasional intermittent urticaria, in rare cases.
- Difficulty breathing or swallowing if it affects the airways.
Causes
The symptoms occur because, when blood vessels dilate, plasma leakage increases, allowing fluid to enter nearby tissues. Although the exact causes of angioedema are unknown in most cases, some identified triggers include:
- Insect bites.
- Certain foods: eggs, shellfish, fish, nuts.
- Allergy medications.
- Certain drugs such as nonsteroidal anti-inflammatory drugs, acetylsalicylic acid, opioids, or angiotensin-converting enzyme (ACE) inhibitors used to lower blood pressure.
Risk Factors
The risk of developing angioedema increases if there is a family or personal history of urticaria or angioedema.
Complications
Angioedema is usually a mild condition, but it can become life-threatening if swelling obstructs the airways due to tongue or throat inflammation.
Prevention
Angioedema can only be prevented if the triggering agent is identified, allowing its avoidance.
Allergy tests can be performed if an allergic reaction is suspected.
What kind of doctor treats angioedema?
Angioedema is diagnosed and treated in immunology consultations. It is also studied and treated in allergology and dermatology consultations. In cases of alarm symptoms, it is managed in emergency care.
Diagnosis
To diagnose angioedema, medical history and symptoms are evaluated, followed by a physical examination. A blood test can then detect high histamine levels or a deficiency of the C1 inhibitor.
Treatment
There is no cure for angioedema. Treatments aim to relieve symptoms and prevent recurrence.
For mild cases, medications such as antihistamines (to reduce the allergic reaction) or corticosteroids (to reduce inflammation) are used. In other types of angioedema, intravenous administration of a C1 inhibitor preparation or subcutaneous administration of bradykinin receptor blockers can be used, with the advantage that the patient can self-administer at home.
If alarm symptoms occur (respiratory difficulty, chest pain, tongue or throat swelling…), hospital care is required, and treatment may include an epinephrine injection and oxygen therapy.
