Spider veins

Telangiectasia
Characteristic lip telangiectases.
Classification and external resources
Specialty	Dermatology
ICD-10	G11.3, I78.0, M34.1
ICD-9-CM	362.15, 448.0
DiseasesDB	27395
MedlinePlus	003284
MeSH	D013684
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Telangiectasias /tɛlˌæn.dʒiː.ɛkˈteɪ.zi.ə/, also known as spider veins or angioectasias, are small dilated blood vessels near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter.

These dilated blood vessels can develop anywhere on the body but are commonly seen on the face around the nose, cheeks, and chin. Dilated blood vessels can also develop on the legs, although when they occur on the legs, they often have underlying venous reflux or "hidden varicose veins" (see "Venous reflux" below). When found on the legs, they are found specifically on the upper thigh, below the knee joint, and around the ankles.

Many patients who suffer with spider veins seek the assistance of physicians who specialize in vein care or peripheral vascular disease. These physicians are called vascular surgeons or phlebologists. More recently, interventional radiologists have started treating venous problems.

Some telangiectasia are due to developmental abnormalities that can closely mimic the behaviour of benign vascular neoplasms. They may be composed of abnormal aggregations of arterioles, capillaries, or venules. Because telangiectasias are vascular lesions, they blanch when tested with diascopy.

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