Hereditary Haemorrhagic Telangiectasia (HHT)

Station 5: Hereditary Haemorrhagic Telangiectasia (HHT) (also known as Osler-Weber-Rendu syndrome)

In station 5 you may be asked to assess a patient with nosebleeds or anaemia e.g. Hb 90, MCV 71

Spend 3 minutes taking a focussed history:

  • Take a history of the nosebleeds
    • Enquire about the timing of the nosebleeds- since when did they start occurring, how often do nosebleeds occur etc.
    • How severe are they? How much blood is lost with each nosebleed?
    • Any trauma to nose?
    • Both nostrils?
    • What do you do when you get a nosebleed?
    • Ever needed to go to hospital because of nosebleed/ ever needed a blood transfusion/iron replacement
  • Any bleeding elsewhere? E.g. haematemesis/melaena, haemoptysis, haematuria, menorrhagia, bleeding after tooth removal etc.
  • Does the patient have symptoms of anaemia?
    • Ask about tiredness/SOB/Chest pain/palpitations/dizziness on standing
    • Ask about other causes of anaemia as these can coexist and exacerbate the underlying anaemia. Ask about dietary intake, blood loss- not covered above such as any travel (hookworm), NSAID use , ask about malabsorption symptoms such as can occur with coeliac disease and crohns disease
    • Pregnant?- this can complicate HHT and needs specialist assessment and management
  • Screen for symptoms of arteriovenous malformations (AVMs) at certain sites:

Resp eg. SOB, chest pain, haemoptysis

GI eg. Blood in stools, black stools, vomiting blood

Liver eg. Jaundice, abdo pain

Neuro eg. Headache, seizures, weakness, sensory loss, speech, vision

GU eg. Haematuria

  • PMH eg. hypertension
  • Dx- any blood thinners? Iron tablets?
  • Fx of bleeding (specifically nose bleeds and HHT)
  • Sx: cocaine use can cause nosebleeds

Spend 3 minutes examining the patient:

  • Hands- telangiectasia, clubbing, koilonychia
  • Eyes- conjunctival pallor, conjunctivae, jaundice
  • Nose- nostrils for evidence of abnormality
  • Mouth- lips, tongue, mucosa for telangiectasia, angular stomatitis, glossitis
  • Examine CVS, Resp, Abdo, Neuro systems quickly. Listen for bruits.
  • Say that you would do a PR in context of IDA
  • Offer to perform fundoscopy if time allows

ICE + Explanation (2 minutes)

A suggested explanation is as follows:

“There are lots of causes for nosebleeds but I suspect it may be related to the lesions on your skin. I will refer you to an ear, nose and throat doctor because of the frequency and severity of the nosebleeds. I will check your blood count today and iron level.  It may be that you need a blood transfusion or to start iron tablets. I suspect you may have a condition called Hereditary Haemorrhagic Telangiectasia which can involve other organs and cause bleeding elsewhere so I need to do some tests to screen for this”



The condition is characterised by vascular dysplasia which causes telangiectasia. Mucosal involvement manifests as epistaxis which is the main cause of anaemia in this condition.

Arteriovenous malformations (AVMs), particularly of the lungs, liver and brain, can occur.

It is inherited in an autosomal dominant fashion. Most cases are due to mutations in the endoglin on chromosome 9 or activin receptor like kinase-1 on chromosome 12.

There may be telangiectasia and AVMs in the GI tract causing acute haemorrhage or chronic slow bleeding with resulting iron-deficiency anaemia.

Pulmonary AVMs occur may present as dyspnoea, cyanosis, bruits, high-output heart failure, clubbing and paradoxical cerebral emboli that may cause stroke and cerebral abscess. They can also lead to haemoptysis and haemothorax. Pulmonary hypertension can occur.

AVMs in the liver can cause high-output cardiac failure or cirrhosis.

Some patients have cerebral involvement resulting in headache, seizures or epilepsy, intracranial haemorrhage and stroke.

Vascular malformations of the urinary tract are rare.


Tests for Osler Weber Rendu:

  1. Bloods including FBC, clotting, blood film, haematinics and iron studies
  2. Hepatic AVM- LFTs, liver USS
  3. Lung AVM- sats, ABG, CXR, CT
  4. GI AVM- OGD+colonoscopy
  5. Cerebral AVM- CT head, MRI brain/MRA
  6. Bladder AVM- urine dip


How is the diagnosis made?

Diagnosis is made using the Curacao Criteria.  If 3 criteria are present the diagnosis is definite.  If 2 criteria are present, the diagnosis is suspected or possible. If only 1 criterion is present the diagnosis is unlikely.

  1. Epistaxis that is spontaneous and recurrent
  2. Multiple mucocutaneous telangiectasia at characteristic sites such as the lips, nose, tongue and mucous membranes, fingers, conjunctiva
  3. Visceral lesions- GI telangiectasia, Pulmonary, Hepatic, Cerebral AVMs
  4. Family History in a first degree relative. Genetic testing can be performed to confirm the diagnosis if necessary.

What are other causes of epistaxis?

  1. Trauma
  2. Low platelets
  3. Drugs- antiplatelets etc
  4. Malignancy
  5. Cocaine
  6. Wegener’s granulomatosis (now called Granulomatosis with Polyangiitis)

What is the management of the condition?

Management of epistaxis and iron deficiency anaemia are the cornerstones of HHT management

A number of topical, systemic, and surgical treatments are available for preventing and managing epistaxis such as nasal humidification, ointments, saline spray, tranexamic acid, tamoxifen, thalidomide, laser therapy or cauterisation, laser ablation, septodermoplasty, and unilateral or bilateral surgical closure of the nostrils.  Emergency nasal packing and blood transfusion may be required for severe haemorrhage.

Endoscopically-administered ablation, embolization and/or surgery may be needed for bleeding gastrointestinal lesions.

Iron deficiency anaemia is managed by repletion of iron. Patient should be told to avoid ingestion of absorption inhibitors such as tea within an hour of iron ingestion. If iron absorption is impaired due to concurrent inflammation or disease or if bleeding is severe enough, parenteral iron therapy and/or blood transfusions may be required.

Refer patients for genetic counselling.  Routine screening for pulmonary AVMs is performed after the age of 16 years. Embolization is sometimes recommended. Screening for AVMs at other sites is individualized.

For individuals with symptomatic liver involvement, treatment is directed at optimizing cardiac status and iron stores. If medical management fails, liver transplantation may be needed.

Written by Dr Sarah Kennedy

Resources used to create this article include those listed in the references section of this webpage and also: