Chapter: HHT · Osler’s disease
Article: 1 of 13
Update: Mai 06, 2021
Author(s): Kühnel, Thomas
The name hereditary hemorrhagic teleangiectasia (HHT) describes the obvious features of a disease characterized by dilated vessels with bleeding tendency.
The name reveals three features that are determining factors for the diagnosis when all three are present: heredity, hemorrhage, dilatation of small vessels. (See also the table of Curaçao criteria).
The disease is also called Rendu-Osler-Weber syndrome, named after those who first described it, or Osler’s disease for short. It belongs to the group of rare diseases (orphan diseases) with a worldwide prevalence of 1 : 5000 to 1 : 8000.
Teleangiectasias are dilations of small vessels; arteriovenous shunts (short circuits) are detectable in an advanced stage. The dilated vessels are visible as small red dots on the skin or mucosa. In principle, teleangiectasias can occur in all areas of the skin and also in all mucous membranes. In addition to the nasal mucosa, the mucosa of the gastrointestinal tract is frequently affected.
As well as the small arteriovenous shunts of teleangiectasia, there can also be short-circuit connections (arteriovenous malformations, shunts) of larger vessels. The vessels most commonly affected by larger shunts are those of the pulmonary and hepatic vascular pathways and, less commonly, those of the cerebral circulation.
The leading symptom is almost always nosebleed. It affects well over 90% of patients. The severity varies from only occasional, drip-like bleeding to life-threatening blood loss with a repeated need for transfusions.