|ICD-10||G11.3, I78.0, M34.1|
Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
Telangiectasias, or spider veins, are small dilated blood vessels near the surface of the skin; usually they measure only a few millimeters. They can develop anywhere on the body but commonly on the face around the nose, cheeks, and chin. They can also develop on the legs, specifically on the upper thigh, below the knee joint, and around the ankles.
These are actually developmental abnormalities but can closely mimic the behaviour of benign vascular neoplasms. They may be composed of abnormal aggregations of arterioles, capillaries, or venules.
Chronic treatment with topical corticosteroids may lead to telangiectasia.
Telangiectasias can result in naevus flammeus (port-wine stain), which is a flat birthmark on the head or neck that spontaneously regresses. A port-wine stain, if present, will grow proportionately with the child. There is a high association with Sturge-Weber syndrome, a nevus formation in the skin supplied by the trigeminal nerve and associated with glaucoma, meningeal angiomas, and mental retardation. Finally, spider telangiectasias are a radial array of tiny arterioles that commonly occur in pregnant women and in patients with hepatic cirrhosis. In men, they are related to high estrogen levels secondary to liver disease.
Because telangiectasias are vascular lesions, they blanch when tested with diascopy.
Telangiectasias may occur in a number of diseases:
- CREST syndrome (a variant of scleroderma)
- hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome)
- Ataxia telangiectasia
- Carcinoid syndrome
- Acne rosacea
A common myth is that this condition is caused from crossing your legs too much. There is no research to validate this assumption.
Telangiectasias are often treated with laser or IPL therapy. There have been medication based treatments available for over 50 years. Laser therapy uses light beam that is pulsed onto the veins in order to seal them off, causing them to dissolve. These light-based treatment requires adequate heating of the veins. For optimal results, several laser treatments are usually necessary. A Sclerosant medication is injected into the diseased vein so it hardens and eventually shrinks away.
- ↑ "Treatment of Seborrheic Dermatitis- May 1, 2000 - American Academy of Family Physicians". Retrieved 2007-06-01.
ca:Telangièctasi de:Teleangiektasie nl:Teleangiëctasie sl:Kuperoza