A rare genetic condition called hereditary angioedema (HAE) causes swelling under the skin, in the gut, and in the lungs. In addition to the mouth, throat, hands, feet, face, genitals, and belly, the swelling can be painful, uncomfortable, and even life-threatening if it blocks the airways.
As a result of a gene malfunction, the blood protein C1 inhibitor plays a vital role in controlling inflammation and fluid leakage in the body. These chemicals can become imbalanced if there is not enough C1 inhibitor, or if it does not work properly. As a result, fluid can leak into the tissues, resulting in swelling, if there is not enough C1 inhibitor.
There are three types of HAE:
Type I: People with type I HAE have low levels of the C1 inhibitor protein. This is the most common form, accounting for 85% of cases.
Type II: People with type II HAE have normal levels of the C1 inhibitor protein, but it does not function correctly.
HAE with normal C1 inhibitor: People with this type have normal levels and function of the C1 inhibitor protein, but they have defects in other genes that affect the production or regulation of the chemicals involved in inflammation and fluid leakage.
HAE is inherited in an autosomal dominant manner, which means that a person only needs one copy of the faulty gene from one parent to have the condition. If one parent has HAE, each child has a 50% chance of inheriting it. HAE can also occur spontaneously from a mutation in the gene, even if neither parent is affected.
The main symptom of HAE is swelling, which can occur in different parts of the body. It usually lasts for 2 to 5 days and then goes away on its own. It can also move from one area to another during the same attack. Like allergic reactions, the swelling does not cause itching or hives.
The severity, frequency, and location of the swelling vary from person to person and even from attack to attack. Some people may have attacks every few weeks, while others may have them only once or twice a year. Some common areas where swelling can occur are:
Mouth or throat: Swelling in the mouth or throat can cause difficulty speaking, swallowing, or breathing. This can be very dangerous and requires immediate medical attention.
Hands or feet: Swelling in the hands or feet can cause pain and limit movement and daily activities.
Face: Swelling in the face can affect the eyes, lips, tongue, or cheeks. It can also cause distortion of the facial features and affect the appearance and self-esteem of the person.
Genitals: Swelling in the genitals can cause pain and discomfort, especially during sexual intercourse or urination.
Belly: Swelling in the belly can cause abdominal pain, nausea, vomiting, diarrhea, or constipation. It can also mimic the symptoms of other conditions, such as appendicitis or bowel obstruction.
Some people may experience warning signs before an attack, such as:
Fatigue
Muscle ache
Tingling
Headache
Abdominal pain
Hoarseness
Mood changes
Diagnosing HAE can be challenging, as the symptoms can be mistaken for other conditions, such as allergies, infections, or digestive disorders. A diagnosis of HAE is usually based on the following:
Medical history: The doctor will ask about the symptoms, their onset, duration, frequency, and location. They will also ask about the family history of HAE or similar conditions.
Physical examination: The doctor will examine the affected areas and look for signs of swelling or inflammation.
Blood tests: The doctor will order blood tests to measure the levels and function of the C1 inhibitor protein and other related proteins and chemicals. These tests can help to confirm the diagnosis and identify the type of HAE.
Genetic tests: The doctor may also order genetic tests to look for the specific gene mutations that cause HAE. These tests can help to confirm the diagnosis, identify the type of HAE, and provide information for genetic counseling and family planning.
There is no cure for HAE, but there are treatments that can help to prevent, reduce, or stop the swelling attacks. Depending on the type, severity, and frequency of the attacks, as well as the individual's preferences and goals, there are a number of treatment options.
Medications used to prevent attacks include androgens (male hormones), antifibrinolytics (blood clotting agents), and C1 inhibitor concentrates (replacement therapy).
Medications taken at the onset of swelling or during an attack include C1 inhibitor concentrates, kallikrein inhibitors (chemical blockers), and bradykinin receptor antagonists (chemical blockers).
People may be trained to administer their own medications at home, either through injections or infusions. This can reduce the need to visit a hospital or clinic and give them more control and convenience.
Lifestyle modifications, such as avoiding triggers, managing stress, staying hydrated, and exercising regularly, as well as supportive measures, such as pain relief, ice packs, compression garments, and elevating the affected area, are non-drug therapies.
There is no way to prevent HAE, as it is a genetic condition that is present from birth. However, there are some steps that can help to prevent or reduce the frequency and severity of the attacks, such as:
Stress, injury, surgery, illness, physical activity, medications, hormonal changes, and certain foods can trigger or worsen an attack. It is possible to identify and avoid triggers that affect the person the most by keeping a diary of symptoms and possible triggers.
It may be beneficial for some people to take preventive medications regularly as prescribed by their doctors in order to reduce their chances of having an attack.
An emergency plan for people with HAE is essential, especially if a severe attack involves the throat. Having access to on-demand medications, knowing how to use them, and knowing where their doctor and nearest hospital are should all be included in the plan. It is also important for them to wear a medical alert bracelet or carry a card that identifies their condition and medications.
People with HAE should seek medical attention if they suffer an attack that affects their breathing, swallowing, or speaking, or if they experience severe abdominal pain or vomiting. In addition, if their symptoms do not improve or worsen after they take their medications, or if they experience any side effects from their medications, they should seek medical attention.
