Hereditary Hemorrhagic Telangiectasia (HHT) is a genetic disorder affecting blood vessel formation throughout the body. It is inherited in an autosomal dominant pattern, which means if one parent has it, there is a 50% chance their child will inherit the condition. The condition is caused by a mutation in one of several genes involved in proper blood vessel development. These genetic mutations are permanent, meaning the underlying cause of HHT does not change or resolve over time. This is why the condition cannot simply go away.
How HHT Affects the Body
Instead of a normal capillary network connecting arteries to veins, people with HHT develop direct connections called arteriovenous malformations (AVMs). These abnormal vessels are fragile and prone to bleeding. When these malformations are small and on the skin, they are called telangiectasias. When they are larger and form in internal organs, they are called AVMs.
Common Symptoms and their Progression
Symptoms can vary significantly among individuals, even within the same family, and often progress with age.
- Frequent Nosebleeds (Epistaxis): This is the most common symptom, affecting over 90% of individuals with HHT, and often begins in childhood. The frequency and severity of nosebleeds can increase with age due to the progressive nature of the telangiectasias in the nasal lining.
- Telangiectasias: Small, red or purple spots can appear on the skin, most commonly on the lips, tongue, face, and fingertips. Like nosebleeds, the number of these spots can increase over time.
- Internal Organ AVMs: AVMs can form in critical organs, including the lungs, brain, liver, and gastrointestinal (GI) tract. These can cause life-threatening complications, such as stroke, heart failure, or internal bleeding, especially if left undiagnosed and untreated. GI bleeding often begins later in life, typically after age 50.
Diagnosing HHT
An early and accurate diagnosis is critical for managing HHT and preventing complications. Diagnostic criteria usually involve a clinical evaluation based on a combination of symptoms and family history.
- Clinical Criteria: A specialist looks for the presence of recurrent nosebleeds, visible telangiectasias, and evidence of internal AVMs, combined with a family history of HHT.
- Imaging Tests: Various imaging techniques, such as bubble echocardiograms, CT scans, and MRIs, are used to screen for and locate internal AVMs in the lungs, brain, and liver.
- Genetic Testing: A definitive diagnosis can be made through genetic testing, which identifies the specific gene mutation responsible for HHT. This is also valuable for screening other family members.
Managing HHT: Treatment Options
Since HHT cannot be cured, treatment focuses on managing symptoms, controlling bleeding, and preventing complications. A multidisciplinary team of specialists is often necessary for comprehensive care.
Addressing Frequent Nosebleeds
- Home Remedies: Using saline nasal sprays, humidifiers, and special moisturizing gels to keep nasal passages moist.
- Ablative Therapies: For more severe cases, procedures like laser therapy or electrocautery can be used to destroy the bleeding vessels.
- Medications: Topical or oral medications, including anti-angiogenic drugs like bevacizumab, can reduce the severity of nosebleeds.
Dealing with Internal AVMs
- Embolization: This minimally invasive procedure involves blocking blood flow to an AVM using catheters and blocking agents like coils or plugs. It is commonly used for lung and brain AVMs.
- Surgery: In some cases, surgical removal of a large or dangerous AVM may be necessary.
- Radiosurgery: Focused radiation beams can be used to treat brain AVMs.
Systemic Drug Therapies and Anemia Management
- Anti-angiogenic drugs: Medications such as bevacizumab can help reduce bleeding systemically by targeting the abnormal blood vessels.
- Anemia Management: Chronic bleeding often leads to iron-deficiency anemia, which can be treated with oral iron supplements, intravenous (IV) iron infusions, or, in severe cases, blood transfusions.
Living and Aging with HHT
Managing HHT is a lifelong process that requires ongoing monitoring and vigilance.
Lifestyle Adjustments and Precautions
- Avoid Blood Thinners: Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen should be avoided as they can increase bleeding risk.
- Preventative Screenings: Regular imaging scans are essential for monitoring existing AVMs and detecting new ones.
- Humidification: Using humidifiers, especially at night, can help with dry nasal passages and reduce nosebleeds.
Mental Health and Support Systems
- Emotional Support: Living with a chronic, unpredictable condition can be emotionally challenging. Support groups and counseling are vital resources.
- Specialist Centers: Seeking care at an HHT Center of Excellence ensures access to a multidisciplinary team with specific expertise in managing the disorder. For example, the non-profit organization Cure HHT offers extensive resources and support.
HHT Management vs. Cure: A Comparison
| Aspect | HHT Management | HHT Cure |
|---|---|---|
| Focus | Controlling symptoms, preventing complications, and improving quality of life. | Eliminating the underlying genetic cause of the disease. |
| Techniques | Medications, targeted procedures (embolization, laser), surgery, lifestyle changes. | Currently not available, though research into gene therapies continues. |
| Goal | To enable patients to live full, healthy lives despite the condition. | To permanently reverse or stop the abnormal blood vessel formation. |
| Real-World Outcome | Most people can have a near-typical lifespan with proper care. | Not yet achievable. |
Conclusion: Empowering Patients Through Management
While HHT is a permanent genetic condition that cannot go away, it is not a life sentence. With early diagnosis, proactive screening, and comprehensive management, individuals can effectively control their symptoms and significantly reduce the risk of serious complications. Continued research offers hope for future therapeutic advancements, but for now, the focus on diligent management empowers patients to lead full and healthy lives.
