What is Angioneurotic Edema (Angioedema)?
Angioneurotic edema is a medical condition that is often seen in emergency rooms. It causes unpredictable and frequent swelling in the skin and soft tissues, such as the lips, eyes, mouth, throat, and digestive system. This health problem is part of a variety of symptoms that can be caused by allergies, but sometimes it’s not related to allergies at all. Urticaria, commonly known as hives, is part of this symptom spectrum.
If this swelling, known as edema, affects the throat, it can block the airways, which may be life-threatening if not diagnosed and treated in time. Over the years, this condition has been called by other names in medical literature such as fleeting skin bumps, passing skin congestion, shifting swelling, and giant hives. However, since 2007, it has been broadly referred to as angioedema.
What Causes Angioneurotic Edema (Angioedema)?
Angioneurotic edema, or swelling caused by fluid accumulation, can be broadly divided into two types: allergic and non-allergic. The non-allergic version can then be further divided into several categories, one of these is hereditary, usually due to a deficiency in a specific enzyme known as C1-inhibitor. This particular type (Hereditary Angioneurotic Edema) is due to a gene mutation and is passed down through family lines.
Other types of non-allergic angioneurotic edema can come from reactions to medications, unknown causes, or as a result of acquired conditions (like chronic illnesses). Certain drugs such as blood pressure and anti-inflammatory medications, depression medications, birth control pills, certain heartburn medicines, and vaccines may lead to swelling. Certain serious or persistent illnesses including cancers, immune system disorders, and infections can also result in this swelling condition.
In addition to these, other elements can also prompt swelling to occur. These conditions can be brought on by surgery, viral infections, exposure to extreme temperatures, pregnancy, minor injuries (like dental procedures or tongue piercings), mental stress, and even certain foods.
Risk Factors and Frequency for Angioneurotic Edema (Angioedema)
In the United States, about 25% of people will have angioneurotic edema at some point in their lives, leading to over a million emergency department visits every year. Italian data shows that 0.37% of all their emergency department visits are due to angioedema, which is a kind of intense swelling. In Canada, for every 1000 emergency department visits, one is related to angioedema. And in the UK, almost 30% of patients with angioneurotic edema have had to visit the emergency department.
Signs and Symptoms of Angioneurotic Edema (Angioedema)
Angioneurotic edema (ANE) is a medical condition where certain areas of the body swell. This swelling usually affects areas like the face, eyes, lips, mouth, throat, limbs, and genitals. Patients with ANE might also have abdominal pain, vomiting, and a bloated belly due to swelling inside their bowel walls, which can obstruct the bowels. A detailed history, including family and drug histories, helps in diagnosing this condition. For instance, using a type of drug called ACEIs can trigger ANE.
When a person with ANE opens their mouth, you can typically see swelling of the tongue or uvula. Yet, it is still recommended to conduct an examination of the vocal cords, called a laryngoscopy, to get a correct diagnosis. Patients might also experience problems with their airways, which could present as a hoarse voice, noisy breathing, voice changes, difficulty breathing, and wheezing. Therefore, it’s important to check that the patient’s airway is not blocked.
In cases of ANE caused by allergies, individuals might also have itchy hives or skin rashes on their trunk and limbs, which can go away on their own. They might also have a type of swelling in their limbs that does not leave an indentation when pressed, known as non-pitting edema.
Testing for Angioneurotic Edema (Angioedema)
Angioneurotic edema, a type of severe swelling, is usually diagnosed based on symptoms, without needing to wait for blood test results. Standard blood tests can be done to check your blood count, kidney health, and liver function, but they typically don’t help in diagnosing angioneurotic edema. If the swelling is due to an allergic reaction, the level of a substance called mast cell tryptase in your blood may be higher during the attack. Later on, in the recovery stage, it can be tested again for comparison. For a certain type of angioneurotic edema called HANE, a component of your blood’s immune system called C4 might be lower than usual during an attack, indicating a lack of another component called C1 esterase inhibitor.
Treatment Options for Angioneurotic Edema (Angioedema)
Treating angioneurotic edema, a type of swelling, should start as early as possible. Some patients might need help with their breathing, such as using a tube to open up their airways. Two types of this condition, HANE and AANE, do not respond well to certain common treatments like antihistamines, corticosteroids, and epinephrine. Instead, these types should be treated with a special concentrate (C1 Inhibitor concentrate), ecallantide which is a kallikrein inhibitor, or icatibant, a bradykinin-receptor antagonist.
Icatibant is effective as a treatment on its own and can be administered at home. Before performing any high-risk procedure on these patients, it is important to give preventative treatment known as prophylaxis. For HANE and AANE, long-term preventative treatment typically involves C1 esterase inhibitors and androgens. Most cases of AANE show no symptoms and get better with immunochemotherapy.
Quick treatment for sudden attacks can be achieved with icatibant and the C1 inhibitor concentrate, while preventative measures include a drug called rituximab, with or without chemotherapy and splenectomy (removal of the spleen). People with HANE can be sensitive to certain triggers, like extensive dental work, requiring short-term preventative treatment before such procedures.
During pregnancy, it is advised to use a specially purified form of C1-inhibitor. However, in immediate episodes, icatibant can be used as it is safe with no harm reported to the mother and her baby. C1 esterase inhibitors are also safe for children under 12 years old.
For children, the doses of these inhibitors vary according to weight. Icatibant is generally well accepted in children and might be useful in treating angioedema caused by a type of blood pressure medicine known as angiotensin-2 receptor blocker. Where life-threatening swelling occurs in oral or tongue muscles, icatibant treatment can be given with rapid effects. Careful monitoring is recommended when combining ACE inhibitors (a type of blood pressure medicine) with an enzyme known as dipeptidyl peptidase-4 inhibitors as it can affect the breakdown of bradykinin, a molecule involved in this type of swelling.
What else can Angioneurotic Edema (Angioedema) be?
When there are symptoms like hives, vomiting, abdominal pain, and fast heart rate, several conditions might be causing them. This could be some severe allergic reactions, where certain allergens trigger the release of substances that cause itching hives and swelling in the intestine lining. This reaction, leading to a drop in blood pressure and increased heart rate due to changes in blood vessels, can be controlled by medicines like adrenaline, antihistamines, and steroids, which can also lower the risk of repeated allergic responses.
Additional conditions that could be causing these symptoms include cellulitis (a skin infection), contact dermatitis (a skin reaction to a particular substance), lymphedema (swelling, usually in the arms or legs), erysipelas (a type of skin infection), and systemic lupus erythematosus (a disease that causes your immune system to attack your own tissues).
What to expect with Angioneurotic Edema (Angioedema)
An attack of a condition known as angioneurotic edema (ANE) can happen at any time after the first exposure, and it may recur in some patients. However, the time it takes for a person to develop hypersensitivity and recover from it is not known.
If there’s a suspected case of ANE in the family, screening is crucial to identifying other family members who might be prone to the condition. As a part of managing ANE, a potentially fatal condition due to throat swelling is relatively common. To manage this, doctors provide training for self-treatment using a medicine called C1 esterase which can stop ANE attacks as soon as the patient feels they need it.
Tranexamic acid, a drug believed to work on a body chemical known as prostaglandin, has also been used to prevent ANE. It has shown to reduce the frequency of episodes and has been used when an attack occurs. However, it typically takes 24 to 72 hours for symptoms to completely resolve after taking this drug.
Possible Complications When Diagnosed with Angioneurotic Edema (Angioedema)
Severe and potentially deadly complications can happen if a type of severe swelling known as angioneurotic edema is not quickly treated. One of these complications is swelling in the larynx (the part of the throat containing the vocal cords) which can lead to low oxygen levels, blockage of the airway, and even death. If the potential for airway problems is not recognized, the chances of severe outcomes, including death, increase.
Preventing Angioneurotic Edema (Angioedema)
Patients should be informed to stay away from anything that causes swelling due to fluid build-up under the skin, if they are aware of such triggers. If certain medications are causing this swelling, it would be beneficial for them to stop using those medications and look for alternatives. If the patient’s condition leads to severe attacks that need epinephrine, a type of medicine usually used in emergencies, they should be given an EpiPen prescription before leaving the hospital. Those who have a similar condition but it’s linked to the immune system, should see a doctor who specializes in immune system disorders. They will also need to be seen regularly at an allergy clinic to confirm their diagnosis.
