Thrombophlebitis involves inflammation of a vein caused by a blood clot inside. With superficial thrombophlebitis, the clot is in a vein just below the surface of the skin.

Superficial thrombophlebitis may occur after the recent use of an intravenous (IV) line, after trauma to the vein, or for no apparent reason in persons at risk for thrombophlebitis.

Risks for superficial thrombophlebitis include the following:

• Disorders that involve increased blood clotting
• Infection
• Varicose veins
• Chemical irritation of the area
• Sitting or being immobilized for a prolonged period

The risk is also increased in women who are or were recently pregnant, and by the use of oral contraceptives.

Superficial thrombophlebitis may be associated with Factor V Leiden, prothrombin gene mutation, and, occasionally, abdominal cancers (such as carcinoma of the pancreas), deep vein thrombosis, and thromboangiitis obliterans.

• Skin redness or inflammation along a superficial vein
• Warmth of tissue around a superficial vein
• Tenderness or pain along a superficial vein (worse when pressure is applied)
• Limb pain
• Hardening of a superficial vein (induration) -- the vein feels cord-like

Your health care provider will diagnose superficial thrombophlebitis based primarily on the appearance of the extremity. Frequent checks of the pulse, blood pressure, temperature, skin condition, and circulation may be required.

The diagnosis of superficial thrombophlebitis may be confirmed with the following tests:

• Doppler ultrasound
• Duplex ultrasound
• Venography

If infection is suspected, cultures of the skin or blood cultures may be performed.

Superficial thrombophlebitis may be associated with deficient blood levels of:

• Antithrombin III (AT-III)
• Protein C (PC)
• Protein S (PS)