Summary about Disease
Osler-Weber-Rendu disease, also known as hereditary hemorrhagic telangiectasia (HHT), is a genetic disorder that causes abnormal blood vessel formation. These abnormal vessels, called telangiectasias, are fragile and prone to bleeding, often in the nose, skin, mucous membranes, and organs like the lungs, brain, and liver. HHT can lead to various complications, including anemia, stroke, and pulmonary hypertension.
Symptoms
Nosebleeds (epistaxis): The most common symptom, often starting in childhood.
Telangiectasias: Small, red or purple spots on the skin, lips, tongue, inside the nose, and fingers.
Gastrointestinal bleeding: Can lead to anemia.
Shortness of breath: May indicate lung involvement (pulmonary arteriovenous malformations - PAVMs).
Seizures or stroke: May indicate brain involvement (brain arteriovenous malformations - AVMs).
Fatigue: Often due to anemia from chronic blood loss.
Headaches: Can be associated with brain AVMs.
Causes
HHT is caused by genetic mutations in genes involved in blood vessel development and repair. These genes typically regulate the transforming growth factor-beta (TGF-β) signaling pathway. The most common genes involved are:
ENG (Endoglin)
ACVRL1 (Activin A receptor type II-like 1, also known as ALK1)
SMAD4 HHT is inherited in an autosomal dominant pattern, meaning that only one copy of the mutated gene is sufficient to cause the disorder.
Medicine Used
Treatment focuses on managing symptoms and preventing complications. Medications may include:
Iron supplements: To treat anemia caused by blood loss.
Topical creams: For bleeding telangiectasias on the skin.
Tranexamic acid: To reduce bleeding.
Bevacizumab: An anti-VEGF antibody used in severe cases to reduce the number and size of telangiectasias.
Estrogen-containing medications: May sometimes be used, but require careful consideration due to potential side effects.
Other targeted therapies: Emerging therapies are being investigated in clinical trials.
Is Communicable
No, HHT is not communicable. It is a genetic disorder and cannot be spread from person to person.
Precautions
Avoid medications that increase bleeding risk: Such as aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) unless specifically directed by a doctor.
Avoid activities that could lead to head trauma: To minimize the risk of bleeding.
Use humidifiers: To prevent nasal dryness and reduce nosebleeds.
Moisturize nasal passages: With saline sprays or gels to keep them hydrated.
Genetic counseling: For individuals with HHT who are planning to have children.
Regular screening: For PAVMs and brain AVMs.
Inform healthcare providers: About your HHT diagnosis before any procedures or surgeries.
How long does an outbreak last?
HHT is a chronic condition, not an acute "outbreak". Telangiectasias are permanent, and the frequency and severity of bleeding episodes can vary over time. The duration of nosebleeds or GI bleeds can range from a few minutes to several hours or days, depending on their severity. There are no outbreaks, this is a condition that lasts their entire life.
How is it diagnosed?
Diagnosis is based on the Curaçao criteria, which includes the following:
Nosebleeds: Spontaneous and recurrent.
Telangiectasias: Multiple, characteristic locations (lips, nose, fingers, etc.).
Visceral involvement: Arteriovenous malformations (AVMs) in the lungs, brain, liver, or gastrointestinal tract.
Family history: A first-degree relative with HHT. A diagnosis of HHT is considered definite if three or more of these criteria are met. Genetic testing can also be used to confirm the diagnosis. Screening for AVMs is done via imaging techniques like MRI, CT scans, and ultrasound.
Timeline of Symptoms
Childhood: Nosebleeds often begin. Telangiectasias may be present but not always obvious.
Adolescence/Young Adulthood: Telangiectasias become more noticeable. Gastrointestinal bleeding may start. Screening for PAVMs is usually recommended during this period.
Adulthood: Symptoms can worsen, and complications related to AVMs in various organs may develop. Anemia is common due to chronic blood loss.
Throughout Life: The severity of symptoms can vary, and ongoing monitoring and management are crucial.
Important Considerations
Multidisciplinary Care: Management requires a team of specialists, including pulmonologists, gastroenterologists, neurologists, otolaryngologists (ENTs), and geneticists.
Screening for AVMs: Regular screening is crucial to detect and treat AVMs before they cause serious complications.
Anemia Management: Maintaining adequate iron levels is essential to prevent fatigue and other complications associated with anemia.
Pregnancy: Women with HHT should be closely monitored during pregnancy due to the increased risk of bleeding and other complications.
Genetic Counseling: Family members should be offered genetic counseling and testing to determine their risk of inheriting HHT.
Individualized Treatment: Treatment plans should be tailored to the specific symptoms and complications experienced by each individual.