Osler's disease is a hereditary disease of the vascular connective tissue, also known as hereditary haemorrhagic telangiectasia (HHT). The disease is named after the Canadian physician Sir William Osler (1849 - 1919). The genetic changes lead to vascular dilatation, which can affect the entire body. This results in a wide range of mild to severe symptoms, which make holistic recognition and treatment essential.
As it is a systemic disease, the entire body can be affected. The severity of the symptoms varies greatly. The formation of so-called telangiectasias is typical. These are red, flat or raised changes in the skin and mucous membranes of the nose, mouth and gastrointestinal tract, which are also known as "Osler spots". These spots are mainly found in the nasal mucosa and lead to the main symptom of nosebleeds, which can be found in over 90% of patients. Less common are stomach or intestinal haemorrhages, which often go unnoticed and can lead to anaemia. As large amounts of blood can quickly accumulate in the gastrointestinal tract, unrecognised bleeding can be life-threatening.
Due to short circuits in the pulmonary circulation, part of the blood does not take part in the gas exchange. This can lead to a reduced oxygen concentration, although in most cases this does not restrict the patient's everyday life. In addition, bacteria or blood clots (e.g. as a result of an accident/injury) can be spread via the short-circuit connections, causing vascular blockages (infarcts) or accumulations of pus (abscesses). The very rare infestation of the arteries and veins supplying the brain can lead to cerebral haemorrhages and strokes. Depending on the size of the vascular dilatations and short circuits, infestation of the liver can lead to overloading of the heart.