Hereditary angioedema (HAE) is a hereditary disorder that causes different parts of the body to undergo extreme swelling.
People often refer to this as a ‘attack’ when symptoms occur. HAE is a chronic condition, so these episodes can occur throughout the life of a person.
Discover the causes, frequency, causes, and treatments of HAE attacks below. We also look at the symptoms involved in these attacks and the three main forms of HAE are identified.
What are HAE attacks?
HAE is a chronic genetic disorder that causes repeated swelling of the mucous membranes and areas of the skin. Throughout the body, this swelling can affect different areas.
Factors such as stress or trauma can cause a HAE attack. For no discernable cause, attacks can also occur.
HAE episodes frequently start early in the life of a person, often no later than the age of 13, and some individuals experience their first symptoms before turning 7. Their symptoms can become more serious as a person ages.
If an attack happens, HAE therapies focus on avoiding new attacks and decreasing the severity of symptoms. Within 12–72 hours of their onset, the symptoms frequently vanish.
The frequency of HAE attacks varies from individual to individual.
78.7 percent reported witnessing an assault during the past month in a 2020 survey of 445 respondents living with HAE. The average number of confirmed attacks over a span of 6 months was approximately 11.
The survey also states that, depending on demographic data, the frequency of attacks varies. For instance, the number of recorded attacks is influenced by age, sex, race, and type of HAE.
In individuals with the condition, several factors can trigger HAE attacks.
The researchers split their participants into two classes in a small study that examined these causes.
In the first category, mental stress, which accounted for about 21% of identified triggers, was the most frequently recorded cause.
These participants could only identify a trigger during the course of the 7-year study in about 30 percent of the more than 3,000 attacks they reported.
The second group of the study reported attacks and triggers over a span of 7 months. 365 attacks were registered by the participants, of which 67 percent occurred on days with identifiable possible triggers.
The most frequently recorded triggers of the second group included:
- mental stress
- physical exertion
- changes in the weather
The U.S. Hereditary Angioedema Association have identified similar triggers. They report that the most common triggers include:
- illnesses such as the common cold or flu
- minor injurires
They also note that people with HAE report symptoms occurring during or after activities such as:
- writing for long periods
- mowing the lawn
- other physical activities
An individual with HAE during their life appears to experience varying degrees of symptoms. In different regions, the signs of a typical HAE attack include swelling, including:
- skin on the hands, genitals, buttocks, feet, legs, and arms
- throat, including the tongue
- other organs
It may cause changes in appearance, a loss of function, and discomfort when the swelling affects the skin. Within 12-72 hours, the symptoms usually go away.
It may cause gastrointestinal symptoms such as diarrhea, discomfort, and vomiting when swelling happens in the abdomen.
It can rapidly become a life-threatening emergency if swelling occurs around the throat or tongue. Urgent medical care should be offered to someone who has difficulty breathing.
What causes each type of HAE?
Three key forms of HAE exist. In an individual with type 1, enough C1 inhibitor proteins are not developed by the body. The body produces enough of these proteins in a person with type 2, but they don’t function properly.
Type 3 HAE is also known as estrogen-dependent HAE. The body produces sufficient and properly functioning C1 inhibitors. The attacks are associated with an increase in estrogen from factors such as pregnancy and hormonal contraceptives.
Care focuses on avoiding attacks and if attacks arise, reducing the severity of the symptoms.
Emergency medical attention may be life saving if HAE damages the airways and breathing of a person.
HAE attacks can be treated directly or indirectly by seven drugs. They include:
- Berinert: This is an intravenous C1 inhibitor concentrate made from human plasma that treats HAE attacks in children and adults.
- Cinryze: Another intravenous medication, this is a C1 esterase inhibitor that prevents HAE attacks in children, teens, and adults.
- Haegarda: This is a self-administered, plasma-derived concentrate of C1 esterase inhibitor that treats symptoms of HAE.
- Ruconest: This is an intravenous, plasma-free recombinant C1 inhibitor concentrate that treats HAE attacks in teens and adults.
- Ecallantide (Kalbitor): This is an injection of a kallikrein inhibitor that treats acute HAE attacks in people who are at least 12 years of age.
- Icatibant (Firazyr): This is an injected B2 bradykinin receptor antagonist that treats acute HAE attacks in people who are at least 18 years of age.
- Lanadelumab-flyo (Takhzyro): This plasma-based kallikrein inhibitor injection prevents HAE attacks in people who are at least 12 years of age.
A child with HAE from a parent has an increased chance of the disorder progressing. Speak to a child’s doctor about any HAE harm. Working with the doctor to establish the most efficient treatment plan is crucial.
HAE attacks cause different parts of the body to swell seriously. If the swelling affects the abdomen, a person might experience gastrointestinal symptoms. If it affects the throat, emergency treatment may be required for the person.
Work with a specialist to determine the drugs that avoid HAE attacks most effectively and decrease the severity of any symptoms that occur.