What is hereditary hemorrhagic telangiectasia?
Hereditary hemorrhagic telangiectasia is a disorder that affects blood vessels. It can cause bleeding in the digestive tract, anemia, increased risk of stroke and other symptoms. In most cases, hereditary hemorrhagic telangiectasis (HHT) isn’t life-threatening and symptoms can be effectively managed.
With HHT, also known as Osler-Weber-Rendu disease, some of the networks of blood vessels that join arteries to veins (capillaries) aren’t correctly formed. In small blood vessels, these abnormalities are called telangiectases. When they occur in larger vessels, they’re called arteriovenous malformations (AVMs). People who have HHT may have both kinds of malformations.
How common is hereditary hemorrhagic telangiectasia?
The incidence of hereditary hemorrhagic telangiectasia is difficult to determine because the severity of symptoms can vary widely and some symptoms, such as frequent nosebleeds, are common in the general population. In addition, arteriovenous malformations may be associated with other medical conditions. Hereditary hemorrhagic telangiectasia is widely distributed, occurring in many ethnic groups around the world. It is believed to affect between 1 in 5,000 and 1 in 10,000 people. Please discuss with your doctor for further information.
What are the symptoms of hereditary hemorrhagic telangiectasia?
The most common sign of HHT is telangiectases in the nose and the most common symptom is recurring nosebleeds. The first sign of HHT usually does not occur until puberty or adulthood with the average age of the first nosebleed occurring at 12 years. Bleeding may occur as often as everyday or as infrequently as once a month. Recurrent nosebleeds are seen in 50-80% of patients with HHT.
Telangiectases in other parts of the body is not usually seen until after puberty and is most apparent in people aged between 20 and 40 years. It occurs in about 95% of patients with HHT. Telangiectasia of the skin and mucous membranes has the following characteristics:
- Appearance of small red to purplish spots or dark red lacy lines on the skin and mucous membranes
- Lesions may occur anywhere but especially on the upper half of the body including the face, inside the mouth and nostrils, lips, ears, conjunctiva of the eyes, forearms, hands and fingers. They are often conspicuous in the nail beds.
- Lesions may initially appear subtle but become quite prominent by late adulthood
- Telangiectases on the skin and mouth can bleed but are less likely to than those in the nose
In addition to visible telangiectases, abnormal blood vessel formation may occur in many other organs. Telangiectases can be found anywhere in the gastrointestinal (GI) system, including the oesophagus, stomach, and small and large intestines. GI bleeding occurs in about 25% of patients with HHT and the risk is increased in patients older than 50 years. Black or bloody stools and/or anaemia (low blood count) are the presenting symptoms. Other organs that may be affected include the lungs (AVM in the lungs occur in about 30% of patients with HHT) and central nervous system (brain and spinal AVM).
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes hereditary hemorrhagic telangiectasia?
The two major types of HHT are HHT1 and HHT2. They are caused by mutations in the endoglin (ENG) and activin receptor-like kinase type 1 (ACVLR1) genes found on chromosome 9 and 12 respectively. Two other genes have also been identified. A defect in just one of these genes causes an abnormality in the formation of blood vessels, which may easily rupture and bleed. The abnormal blood vessels are known as telangiectases, or arteriovenous malformations (AVM) if larger blood vessels are involved.
The vascular endothelial growth factor, VEGF, may modulate angiogenesis in HHT.
What increases my risk for hereditary hemorrhagic telangiectasia?
Please discuss with your doctor for further information.
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is hereditary hemorrhagic telangiectasia diagnosed?
Signs and symptoms of telangiectases and arteriovenous malformations (AVMs) include nosebleeds, red or purple spots, lacy red vessels, shortness of breath, migraine headaches, iron deficiency anemia, fatigue, and blood in the stool.
A clinical diagnosis of HHT can be made if you have at least three of these four criteria:
- Recurrent nosebleeds that seem to start for no reason
- Visible telangiectases on your lips, mouth, fingers, nose and the inside of your mouth
- Internal telangiectases or AVMs in your lungs, brain, spine, digestive tract or liver
- Family history of a parent, sibling or child with HHT
Your doctor may diagnose HHT based on a physical examination, results of imaging tests and a family history. But some symptoms may not yet be apparent in children or young adults. Your doctor may also suggest you undergo genetic testing for HHT, which may confirm a suspected diagnosis.
Your doctor can refer you to a certified genetic counselor or medical geneticist, who can talk with you about how genetic testing for HHT may be useful for you and your family. HHT is a disorder you inherit from one of your parents. It’s called an autosomal dominant disorder, which means that if one of your parents has HHT, you have a 50-50 chance of inheriting the dominant gene responsible for HHT. If you inherit this gene, you will have HHT.
As part of determining a diagnosis, your doctor will likely have you under one or a combination of the following imaging tests:
- Chest X-ray. A chest X-ray can help your doctor see the size, shape and structure of your lungs. It can also give clues about the location and severity of any arteriovenous malformations (AVMs).
- Ultrasound imaging. This technique is sometimes used to determine whether the liver is affected by AVMs.
- Magnetic resonance imaging (MRI). Your doctor may order an MRI scan to check your brain for any blood vessel abnormalities.
- Bubble study. To screen for any abnormal blood flow caused by an AVM in your lung, your doctor may recommend a contrast echocardiography, also called a bubble study. It uses sound waves to examine the blood flow through your vessels. With bubble echocardiography, you’ll receive an injection of saline solution that has air bubbles in it, making it easier for your doctor to see vessel malformations and blood flow.
- Computerized tomography (CT) scan. This imaging test combines a series of X-ray views taken from many different angles and computer processing to create cross-sectional images of the bones and soft tissues inside your body. If a bubble echocardiogram reveals you may have a lung AVM, your doctor may order a CT scan of your lungs to confirm the diagnosis and assess whether you need surgery.
- Colonosocopy and upper endoscopy. People with HHT due to mutations in the SMAD4 gene may be at increased risk for polyps. If this relates to you, your doctor may recommend screening including a colonoscopy and upper endoscopy.
How is hereditary hemorrhagic telangiectasia treated?
If you or your child has HHT, seek treatment at a medical center with experience treating it. Because the disorder is uncommon, finding a specialist in HHT can be difficult. In the United States, HHT Centers of Excellence, including Mayo Clinic, are designated by the HHT Foundation for their ability to diagnose and treat all aspects of the disorder.
No cure exists for HHT, but treatment can help avoid serious complications caused by abnormal blood vessels. HHT treatment often depends on which parts of the body are affected.
- Telangiectases in the nose can cause bleeding that ranges from minor to severe. Minor nosebleeds may respond to home remedies, such as humidifying the air, using moisturizing nose sprays or drops, and avoiding strong nose blowing. Treatments for more-serious nosebleeds include laser coagulation therapy (ablation) and hormone therapy. People with severe disease affecting the nose may need a procedure called septal dermoplasty.
- Often, people with telangiectases on the skin may choose a wait-and-watch approach. If the blood vessels bleed and discolor the skin, laser therapy is a treatment option. It can selectively destroy the discolored tissue.
- Stomach and intestines. Bleeding in the stomach or the intestines is often difficult to treat due to the large number of telangiectases that may occur in those areas. Treatment may involve laser therapy, a heater probe, hormone therapy or a combination of these.
- If an imaging test reveals you have arteriovenous malformations (AVMs) in a lung, your doctor may suggest treating them even if you don’t have any symptoms. Left untreated, they may cause problems, such as a stroke. One treatment option is sealing off the AVM (embolization) with a procedure called pulmonary angiogram. The radiologist will first guide a thin tube (catheter) through a small incision in the skin of the groin and direct it to the AVM. He or she then stops blood flow to the AVM by placing a tiny balloon or coil.
- Treatment for AVMs in the brain depends on their size, location, whether they are bleeding and your symptoms. Options include surgery, embolization, radiosurgery and, in some cases, observation.
- Rarely, treatment for AVMs in the liver is a liver transplant.
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage hereditary hemorrhagic telangiectasia?
Please discuss with your doctor for further information.
If you have any questions, please consult with your doctor to better understand the best solution for you.
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