The term telangiectasia describes an abnormality of the tiny blood vessels of the skin, which widen or increase in size.
Telangiectasias can develop in all parts of the body. However, they are most frequently noted over the mucous membranes and sclera of the eyes.
In the majority of cases, most of these small telangiectasias are asymptomatic. In other words, it does not cause any symptoms or problems.
History of Hereditary hemorrhagic telangiectasia
- Hereditary hemorrhagic telangiectasia (HHT) is a rare genetic disease associated with the formation of abnormal blood vessels in the skin, mucous membranes, and also in major organs such as the brain, lungs and liver.
- Henry Gawen Sutton, in the year 1864, documented the condition termed as Hereditary hemorrhagic telangiectasia (HHT).
- HHT is also known by two different names such as Osler-Weber Rendu syndrome and Rendu-Osler-Weber syndrome.
- HHT was recorded as a disease entity in 1909, and the term was coined.
- To date, there are more than a million patients affected by the disease.
- There is no gender predisposition since males and females are affected equally.
- The disease is noted with an incidence of approximately 1 per 5,000 people.
Symptoms of Hereditary hemorrhagic telangiectasia
There is a wide variation in the symptoms manifested in HHT. This difference is essentially due to the genetic differences in disease, the specific gene that is mutated or changed in HHT.
A significant group of patients may manifest symptoms during early childhood, and yet another group of patients manifest symptoms only around the thirties, forties or much later in life.
The symptoms of HHT depend on the site and organ affected.
- The first symptom of HHT is nosebleeds that may occur during childhood; however, in some patients, it may manifest around puberty. Nosebleeds are associated with the formation of telangiectasias in the mucus membrane of the nose, which is due to a genetic defect.
- Gastrointestinal bleeding is noticeable in some patients if telangiectasias also occur in the mucosa of the intestinal tract.
- Coughing up of blood and difficulty breathing are noted in those patients with HHT who develop arteriovenous malformations (AVMs) in their lungs.
- Headache, dizziness and seizures are noted in patients with HHT with AVM in their brain.
Diagnosis of Hereditary Hemorrhagic Telangiectasia
The diagnosis of HHT is essentially made on the basis of symptoms, family history and detailed physical examination by a doctor.
Molecular genetic testing is advised for children of an affected parent with HHT. This test will determine the possibility of inheriting the disease from the parent. Each child has a fifty per cent possibility of inheriting the mutation for HHT from their parent.
Standard screening tests for adults with HHT are Haemogram to rule out iron deficiency anaemia.
Additional investigations like MRI may be required to identify vascular defects in organs.
The international consortium for HHT has clearly defined a set of diagnostic criteria for HHT.
The four criteria are as follows,
1. Recurrent spontaneous nosebleeds
2. Presence of multiple telangiectasias in characteristic locations
3. Presence of internal (visceral) telangiectasias or AVMs
4. Family history of definite HHT
A diagnosis is confirmed if an individual has a positive association for a minimum of at least three criteria stated herewith.
The role of Radiology in hereditary hemorrhagic telangiectasia includes the following techniques
- A contrast MRI of the brain with gadolinium to rule out a brain AVM.
- Contrast echocardiography in symptomatic individuals for Pulmonary AVM.
- Imaging of the liver (ultrasound, MRI or CT with contrast), if clinically indicated, is undertaken to document an AVM in the liver.
Treatment of Hereditary Hemorrhagic Telangiectasia
The treatment of HHT is discussed under two modalities such as
- Standard Therapies
- Investigational Therapies
Standard Therapies
- Individuals with nosebleeds must use nasal lubrication with Vaseline or saline spray.
- Nasal blowing or picking of the nose should be avoided.
- Oral tranexamic acid or sclerotherapy may be used if nasal bleeds are recurrent.
- For Individuals with pulmonary AVM with a feeding artery greater than 2 or 3 mm in diameter, transcatheter embolization therapy, with either coils or plugs, is currently indicated.
- For individuals with Brain AVMs, surgical removal, embolization, or focused radiation (gamma knife) of the AVM is indicated.
Investigational Therapies
- Infusions of the drug bevacizumab may be tried on an intermittent basis to reduce nosebleeds, anaemia and GI bleeds in selected individuals.
- Estrogen and progesterone therapy have been indicated to prevent recurrent bleeding associated with HHT.
Long-term follow-up and research are required to understand the effectiveness of these treatments for HHT.
Conclusion
Some problems associated with this disorder are severe and potentially life-threatening. Fortunately, if HHT is discovered early, effective treatments are available though the effectiveness of the treatment has a long way to establish as still researches are going on.
