What’s an HAE Attack?
HAE attacks can cause painful and disfiguring swelling in different parts of your body. There are three types:
Subcutaneous Attacks These attacks affect areas of the skin, usually on the face, hands, feet, or genitals.Abdominal Attacks An abdominal attack causes swelling in the intestinal wall. You might experience stomach pain, nausea, vomiting, or diarrhea.Laryngeal Attacks Swelling in the throat, or laryngeal attacks, are the most dangerous HAE events. If untreated, they can cause your airway to close up.
Attacks can affect one area of the body, or sometimes a combination of areas. RELATED: Living With Hereditary Angioedema (HAE) Type 3 HAE is extremely uncommon. Researchers believe some cases are caused by mutations in the F12 gene, which makes a protein that plays a role in regulating inflammation. They aren’t sure what causes other instances of type 3. Most HAE attacks start because your body needs C1 inhibitor but doesn’t get enough, or the protein doesn’t function like it should. Some triggers can affect your body’s demand for C1 inhibitor. These may include:
Physical activitiesIllnesses or infectionsStressFoodsSurgeries or other medical proceduresHormone changesCertain medicines, such as angiotensin-converting enzyme (ACE) inhibitors or birth control pills
Your Body During an HAE Attack
Without enough or properly functioning C1 inhibitor, a sequence of events occurs that ultimately causes an attack. First, an enzyme in the blood known as kallikrein becomes uncontrolled. When this happens, kallikrein splits a substance called kininogen. The process generates too much of a peptide known as bradykinin. Excessive amounts of bradykinin cause blood vessel walls to leak fluid into body tissues. This leads to fluid buildup and the signature swelling that people with HAE experience. RELATED: Hereditary Angioedema (HAE): Resources to Help You Cope
What About Type 3 HAE Attacks?
With some cases of type 3 HAE, the body also produces too much bradykinin, but it’s because a mutation in the F12 gene creates a protein with increased activity. Researchers aren’t exactly sure what causes other type 3 events. Common signs include:
Swelling and pain that affects the face, hands, feet, genitals, or other areasA non-itchy rashNausea, vomiting, or diarrheaTightening in the throatTrouble talking, breathing, or swallowingHoarseness
RELATED: Hereditary Angioedema, or HAE: What Are Its Causes and Triggers?
What You Should Do When an HAE Attack Happens
An HAE attack that targets your throat is considered a medical emergency. Studies show that without treatment, the risk of death from a laryngeal episode can be as high as 30 percent. You or a loved one should call for medical help if you experience this type of attack. “On-demand” treatments are available to help symptoms of HAE attacks. These medicines either prevent swelling or raise the amount of C1 inhibitor in your blood. You can take them at the first sign of an attack. Every person with HAE should have access to an on-demand therapy to use when having an attack. Additionally, some doctors recommend preventive drugs, which can be taken to reduce the frequency of attacks. Medicines that treat allergic reactions, such as antihistamines or steroids, will not help symptoms of an HAE episode. Be sure to talk to your doctor about your treatment options.
