hereditary hemorrhagic telangiectasia - definition of hereditary hemorrhagic telangiectasia in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia.

Hereditary Hemorrhagic Telangiectasia

Definition

Hereditary hemorrhagic telangiectasia is an inherited condition characterized by abnormal blood vessels which are delicate and prone to bleeding. Hereditary hemorrhagic telangiectasia is also known as Rendu-Osler-Weber disease.

Description

The term telangiectasia refers to a spot formed, usually on the skin, by a dilated capillary or terminal artery. In hereditary hemorrhagic telangiectasia these spots occur because the blood vessel is fragile and bleeds easily. The bleeding may appear as small, red or reddish-violet spots on the face, lips, inside the mouth and nose or the tips of the fingers and toes. Other small telangiectasias may occur in the digestive tract.

Unlike hemophilia, where bleeding is caused by an ineffective clotting mechanism in the blood, bleeding in hereditary hemorrhagic telangiectasia is caused by fragile blood vessels. However, like hemophilia, bleeding may be extensive and can occur without warning.

Causes and symptoms

Hereditary hemorrhagic telangiectasia, an autosomal dominant inherited disorder, occurs in one in 50,000 people.

Recurrent nosebleeds are a nearly universal symptom in this condition. Usually the nosebleeds begin in childhood and become worse with age. The skin changes begin at puberty, and the condition becomes progressively worse until about 40 years of age, when it stabilizes.

Diagnosis

The physician will look for red spots on all areas of the skin, but especially on the upper half of the body, and in the mouth and nose and under the tongue.

Treatment

There is no specific treatment for hereditary hemorrhagic telangiectasia. The bleeding resulting from the condition can be stopped by applying compresses or direct pressure to the area. If necessary, a laser can be used to destroy the vessel. In severe cases, the leaking artery can be plugged or covered with a graft from normal tissue.

Prognosis

In most people, recurrent bleeding results in an iron deficiency. It is usually necessary to take iron supplements.

Prevention

Hereditary hemorrhagic telangiectasia is an inherited disorder and cannot be prevented.

Resources

Organizations

American Medical Association. 515 N. State St., Chicago, IL 60612. (312) 464-5000. http://www.ama-assn.org.

Association of Birth Defect Children. 3526 Emerywood Lane, Orlando, FL, 32806. (305) 859-2821.

Key terms

Autosomal dominant — A pattern of inheritance in which the dominant gene on any non-sex chromosome carries the defect.

Chromosome — A threadlike structure in the cell which transmits genetic information.

telangiectasia /tel·an·gi·ec·ta·sia/ (tel-an″je-ek-ta´zhah) permanent dilation of preexisting small blood vessels, creating focal red lesions.

hereditary hemorrhagic telangiectasia a hereditary condition marked by multiple small telangiectases of the skin, mucous membranes, and other organs, associated with recurrent episodes of bleeding from affected sites and gross or occult melena.

spider telangiectasia vascular spider.

hereditary hemorrhagic telangiectasia

An inherited disease, usually beginning after puberty, characterized by multiple telangiectases and by fragile capillaries that break easily and bleed into the skin and mucous membranes. Also called Rendu-Osler-Weber disease, Rendu-Osler-Weber syndrome.

hereditary hemorrhagic telangiectasia,

a vascular anomaly, inherited as an autosomal-dominant trait, characterized by hemorrhagic telangiectasia of the skin and mucosa. Small red-to-violet lesions are found on the lips, oral and nasal mucosa, tongue, and tips of fingers and toes. The thin, dilated vessels may bleed spontaneously or as a result of only minor trauma, and this condition becomes progressively more severe. Bleeding from superficial lesions is often profuse and may result in severe anemia. No specific treatment is known, but accessible bleeding lesions may be treated with pressure, styptics, and topical hemostatics. Transfusions may be indicated for acute hemorrhage, and iron deficiency anemia may require continuous treatment. Also called hemorrhagic familial angiomatosis, Osler-Weber-Rendu syndrome, Rendu-Osler-Weber syndrome.

telangiectasia (t

lan´jēektā´zh

n 1. the dilation of the capillaries and small arteries of a region. A hereditary form (hereditary hemorrhagic telangiectasia) may appear intraorally.
2. a disorder characterized by cutaneous and mucosal vascular macules, nodules, and arterial spiders that tend to bleed sporadically.

telangiectasia, hereditary hemorrhagic (Rendu-Osler-Weber disease),

n the dilation of small vessels and capillaries resulting from a genetic factor, with a tendency to bleed. Lesions may occur on the tongue as small, raised, red to bluish-red elevations.

Hereditary hemorrhagic telangiectasia.

hereditary hemorrhagic telangiectasia

Osler-Rendu-Weber syndrome, Rendu-Osler-Weber syndrome Molecular hematology An AD condition characterized by telangiectases of mucocutaneous surfaces–tongue, nose, lips, hands, feet Clinical Episodic epistaxis in childhood, chronic GI hemorrhage, palmo-plantar, liver telangiectasias, and lung AV malformations; telangiectasias may be seen on spleen, brain and spinal cord; rupture of the thin-walled vessels may result in hemorrhage of varying severity Treatment Aminocaproic acid, an inhibitor of fibrinolysis. See Endoglin.