Telangiectasias are small dilated blood vessels near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. They can develop anywhere on the body but are commonly seen 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.
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.
Telangiectasia in the legs is often related to the presence of venous hypertension within underlying varicose veins. Flow abnormalities within the medium sized veins of the leg (reticular veins) can also lead to the development of telangiectasia.
Factors that predispose to the development of varicose and telangiectatic leg veins include
Age: The development of spider veins may occur at any age but usually occurs between 18 and 35 years, and peaks between 50 and 60 years.
Gender: Females are affected approximately four to one to males.
Pregnancy: Pregnancy is a key factor contributing to the formation of varicose and spider veins. The most important factor is circulating hormones that weaken vein walls. There’s also a significant increase in the blood volume during pregnancy, which tends to distend veins, causing valve dysfunction which leads to blood pooling in the veins. Moreover, later in pregnancy, the enlarged uterus can compress veins, causing higher vein pressure leading to dilated veins. Varicose veins that form during pregnancy may spontaneously improve or even disappear a few months after delivery.
Lifestyle/Occupation: Those who are involved with prolonged sitting or standing in their daily activities have an increased risk of developing varicose veins. The weight of the blood continuously pressing against the closed valves causes them to fail, leading to vein distention.
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