Hereditary angioedema (HAE) is a rare genetic disorder that can cause swelling attacks in the limbs, face, upper airways, abdomen, and genitalia.
HAE can occur anywhere on the body. The most common areas are the lips, hands, feet, and the skin around the eyes. It also may occur in the mucosal linings of the respiratory and digestive tracts.
Swelling attacks can happen regularly, often without a known HAE trigger. HAE attacks can be prompted by trauma; viral infections; stress; medical and dental procedures, including surgery and having a tooth pulled; hormonal fluctuations; allergens; and physical activity.
HAE attack symptoms include swollen areas of skin that may be smooth or raised. Symptoms can vary from person to person or even from attack to attack in the same person, and can include non-swelling symptoms.
HAE attack treatment includes learning what the triggers are, which are individual to each person, and short- and long-term preventive treatment with medications. With the right medical care, a person may be symptom-free for years.
In some cases, severe swelling may affect the intestines, causing nausea and vomiting, along with intense pain. Some people may have swelling in the mouth and throat, making it difficult to swallow, speak, and breathe. Breathing problems can quickly become life-threatening emergencies and require immediate medical treatment.
HAE attacks are triggered by an overproduction of a protein called bradykinin, which increases blood vessel leakiness and causes edema. Swelling occurs when bradykinin is activated in the deep layers of the skin, causing fluid to flow from the bloodstream into nearby tissues.
There are three types of HAE:
Types 1 and 2 are caused by mutations in the SERPING1 gene, which is involved in making a type of protein called C1-inhibitor. When there isn’t enough of this protein, bradykinin levels can get too high and cause an attack.
Type 3 HAE is caused by mutations in genes other than SERPING1, includingthe F12 gene. These mutations can trigger an inflammatory response and subsequently make bradykinin levels get too high and lead to an attack.
HAE attack triggers
Hereditary angioedema triggers include trauma, viral infections, stress, and medical or dental procedures. Other triggers are allergens, hormonal fluctuations, and repetitive physical activities.
Exposure to common foods or environmental factors can trigger HAE attacks. A small study reported foods including milk, apple, pineapple, onion, garlic, fish, citrus fruits, strawberries, and cheese could be possible triggers. HAE attacks can seem similar to other kinds of allergic reactions.
Changes in hormone levels also can trigger hereditary angioedema attacks.
Puberty can cause HAE symptoms to become more frequent and severe, particularly for girls.
Birth control pills, which contain artificial female hormones, can trigger attacks.
Pregnant women should be monitored by an HAE expert, in addition to their obstetrician-gynecologist. With good management of the disease, most women will have a successful pregnancy and delivery.
Doing repetitive activities that put pressure on one part of the body for a long period of time may trigger swelling attacks in people with HAE. This could include gripping a tennis racket, typing, or tightly holding a tool such as a hammer.
Physical trauma, illness, and medication
Physical trauma, including from surgery or an accident, can cause an HAE attack in the affected area of the body.
Infections are a common trigger for HAE attacks in children and adults, so steps should be taken to limit exposure to viruses and to stay up to date with recommended vaccinations.
High blood pressure medications containing ACE inhibitors may increase the frequency or start of HAE attacks and should be avoided.
A work-life imbalance, family problems, and the loss of a loved one can be some sources of emotional stress. People living with HAE also may find having unexpected, disfiguring, and painful attacks stressful.
Stress can lead to anxiety and depression, and affect quality of life.
Procedures associated with the upper digestive tract, such as surgery or dental surgery, can cause swelling at the site of the surgery, usually within 48 hours.
For example, having a tooth removed causes swelling in more than one-third of people with HAE if preventive treatment is not provided before the procedure.
Tips for avoiding triggers
Everyone who has HAE has a different set of factors that may trigger attacks. Identifying and avoiding them can significantly improve management of the disease.
Keeping a journal describing the attacks and possible triggers can help identify potential causes. It also can be referred to for recalling details when discussing treatment with healthcare providers. Include in the write-up the severity of the attack, possible trigger, treatment method, and response to treatment.
Other ways to avoid triggers include:
Ensure good dental care to reduce the need for dental surgery.
Talk to the surgeon or dentist before any procedure about taking short-term prophylactic (preventive) treatment.
Get a flu shot to reduce upper airway infections and also upper airway swelling.
Practice good hygiene to avoid infections, such as hand washing and wearing a mask when appropriate.
Women should avoid estrogen-containing oral contraceptive agents and estrogen hormone replacement therapy. Instead, try hormonal contraception with progesterone-only pills.
Eat a healthy diet that doesn’t include known allergens.
Get plenty of sleep.
Do gentle physical activities that don’t have the potential for contact with other people or sports equipment that could lead to bodily trauma such as bruising.
Practice meditation, deep breathing, and other mindfulness and relaxation exercises to relieve stress and improve mental health.
For caregivers of children with HAE, the following can be considered:
Children should get all recommended childhood vaccinations, which are considered safe for people with HAE.
Teach children proper hygiene, such as hand washing.
It’s also important to be prepared for an HAE attack. Suggestions include the following:
Create an action plan in case of a health emergency.
Carry on-demand HAE medications and know how to use them.
Carry an HAE identification card with instructions on how to manage attacks.
Provide written instructions to childhood caregivers, such as at day care and school, on avoiding HAE attack triggers and managing symptoms.
Prevention of HAE attacks includes long-term treatment for attack prevention.
Speak with a healthcare provider, especially before starting or changing treatment, as plans can vary based on factors such as age, HAE triggers, comorbidities (other diseases), and other personal preferences.
Treatment should be given as soon as an attack is identified. If the treatment isn’t working, seek medical care from a healthcare professional.
Schedule regular follow-up visits with a primary healthcare provider to monitor the frequency and outcome of preventive treatments, and make changes as necessary.
Angioedema News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
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