Superficial venous thrombosis, commonly called paraphlebitis, refers to the obstruction of a vein by a blood clot. It is a frequent and mild disease, which is easily treated. What are the symptoms ? How is the diagnosis carried out?

A phlebitis (venous thrombosis) is an old term and still commonly used to designate a blood clot “thrombus” which forms and partially or completely blocks a deep or superficial vein. Two types of venous networks coexist: the deep venous network and the superficial venous network. 

If it appears on a varicose vein visible under the skin, then we can speak of “superficial venous thrombosis”. Superficial phlebitis is not serious when isolated, but since the networks communicate, it can spread and be complicated by deep vein thrombosis.

The different causes are: 

• In a paraphlebitis, the clot can be created in a superficial vein, a small vein located between the skin and the muscles (saphenous vein). The saphenous veins are part of a superficial network of veins located under the skin and which can be the site of varicose veins. Varicose veins appear spontaneously or in the presence of risk factors and remain the most common cause of paraphlebitis in the legs;
• Paraphlebitis that arises in a “healthy” vein is often characteristic of an underlying condition such as a genetic or acquired defect in blood clotting, cancer, or a rare inflammatory vascular disease (Behçet’s disease, Burger’s disease);
• A sign of venous insufficiency may be an indication of the arrival of paraphlebitis.

Unfortunately, the signs are not always very precise. However, it results in the occurrence of a stabbing pain that can last for several days. The varicose vein then appears swollen, red, hot, thickened and hard to the touch causing functional discomfort. In addition, it is especially important to remain vigilant in the event of associated risk factors.

In case of superficial phlebitis, the diagnosis is made during the examination, but a venous Doppler ultrasound is useful to rule out the existence of an associated deep phlebitis, present once in four.

The goal of treatment will be to thin the blood. Indeed, it is necessary to avoid an aggravation and an extension of the clot which could:

• Progress towards the deep venous network and then lead to phlebitis or deep vein thrombosis;
• Migrate to the heart and cause pulmonary embolism by blocking the arteries in the lung.

In the vast majority of cases, once treatment begins, the clot attaches to the wall and no longer progresses thanks to anticoagulant treatment or compression stockings.

Anticoagulant therapy

As a first choice, direct oral anticoagulants (DOA) are used for many types of thrombosis depending on the symptoms and signs found during the examination: location, size and extension of the clot. They are easier to use, have less interference with food or other treatments and do not require regular monitoring by blood tests. 

Compression stockings

In addition to drug therapy, sock compression may be prescribed in the early phase. They will help relieve edema in the leg and reduce pain. It is even possible that they act in part on the resorption of the clot. Compression socks are to be worn exclusively during the day and over a long period.

There are different classes but a class 3 will mostly be indicated (there are 4 classes of increasing compressive force). This compression will ensure the treatment of varicose veins.

Finally, paraphlebitis occurring in a varicose vein is an argument for treating varicose veins in order to prevent it from recurring later. To do so, examinations to find the cause will be requested. Among these examinations, there are radiological examinations, or blood tests to look for, for example, a family or genetic blood abnormality, promoting the risk of phlebitis.

Depending on the results, the anticoagulant treatment may be prolonged.

The following situations can favor the occurrence of phlebitis:

• Venous stasis (the blood stagnates in the veins, because of a too long lying or motionless position. This is the most important element);
• A bleeding disorder (your blood clots more easily because of illness or treatment);
• An alteration of the wall of the vein (if an infusion is placed in a vein for a long time, the wall of the vein can be damaged and can become blocked);
• Age over 40;
• Obesity;
• Smoking;
• Immobilization (plaster, paralysis, long trip);
• Pregnancy, contraceptive or menopausal hormone therapy containing estrogen;
• History of phlebitis;
• Cancer, cancer treatment (chemotherapy);
• Chronic inflammatory disease;
• Biological genetic diseases, identified by blood test.

More general rules are also useful for the prevention of phlebitis:

• Mobilization of your muscles by walking and muscle exercises;
• Elevation of the feet of the bed;
• Venous compression by socks worn during the day;
• Venous compression recommended during air travel.