Hereditary Angioedema Symptoms: Causes & Treatment
- A rare genetic condition causing episodes of severe swelling in various body parts.
- Stress, trauma, illness, certain medications, or occur spontaneously.
- Perhaps life-threatening airway swelling requires immediate medical attention.Early diagnosis and treatment are crucial.
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Hereditary Angioedema (HAE): A Comprehensive Guide
Table of Contents
Updated September 26, 2024, 18:57:04 EDT
Understanding Hereditary Angioedema
Hereditary Angioedema (HAE) is a rare, potentially life-threatening genetic disorder characterized by recurrent episodes of swelling in various parts of the body. Unlike common allergic reactions, HAE isn’t caused by histamine release and doesn’t respond to antihistamines or epinephrine. It’s estimated to affect between 1 in 50,000 and 1 in 100,000 people globally [1].
The underlying cause of most HAE cases (Type I and Type II) is a deficiency or dysfunction of the C1 inhibitor protein (C1-INH). This protein regulates the inflammatory response, and its absence or malfunction leads to excessive bradykinin production, a potent vasodilator that causes swelling [2].
Types of Hereditary Angioedema
There are three main types of HAE:
- type I HAE: The most common type (85% of cases), characterized by low levels of C1-INH protein [3].
- Type II HAE: C1-INH protein is present but dysfunctional. This accounts for about 15% of cases [3].
- type III HAE: Not related to C1-INH. It’s associated with mutations in the F12 gene,affecting the contact system of the coagulation cascade [4]. this type is more common in women, frequently enough triggered by pregnancy or hormonal birth control.
Symptoms of Hereditary Angioedema
Swelling is the hallmark symptom of all HAE episodes. However, the location and severity of swelling can vary significantly.Symptoms may depend on the type of attack.
Subcutaneous Attacks
These attacks affect areas of the skin, typically on the face, hands, feet, or genitals. Skin will swell and may turn red,but usually doesn’t itch. Sometimes a skin attack causes temporary disfigurement. The swelling can make it challenging to perform simple activities like walking or holding a pen. Subcutaneous attacks are often mistaken for allergic reactions [5].
Abdominal Attacks
Abdominal attacks involve swelling in the intestinal wall, leading to severe stomach pain, which can be debilitating. Visible abdominal swelling isn’t always present. Other symptoms of an abdominal attack include:
- Nausea
- Vomiting
- Diarrhea
- Severe cramping