Hereditary haemorrhagic telangiectasia





Introduction

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant condition characterised by (as the name suggests) multiple telangiectasia over the skin and mucous membranes. Twenty percent of cases occur spontaneously without prior family history.

Epidemiology

  • Incidence: 2.00 cases per 100,000 person-years
  • Peak incidence: 30-40 years
  • Sex ratio: 1:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Clinical features

Features
  • telangiectasias
  • epistaxis: over 90% of patients suffer from recurrent nose bleeds
  • gastrointestinal haemorrhage
  • anaemia may occur as a result of blood loss

Investigations

Guidelines recommend that patients have radiological/endoscopic evaluation of the:
  • brain
  • lungs
  • gastrointestinal tract

This is to screen for any telangiectasia or arteriovenous malformations (AVM). This is important as certain findings, e.g. cerebral AVMs require specialist management.

Genetic testing is also recommended.

Diagnosis

There are 4 main diagnostic criteria. If the patient has 2 then they are said to have a possible diagnosis of HHT. If they meet 3 or more of the criteria they are said to have a definite diagnosis of HHT:
  • epistaxis : spontaneous, recurrent nosebleeds
  • telangiectases: multiple at characteristic sites (lips, oral cavity, fingers, nose)
  • visceral lesions: for example gastrointestinal telangiectasia (with or without bleeding), pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM
  • family history: a first-degree relative with HHT