The word phlebitis sounds scarier than it usually deserves, but it shouldn't be ignored either. It's the inflammation of a vein just under the skin, with a small clot inside, and in most cases it's less serious than deep thrombosis.
What phlebitis is
Phlebitis means inflammation of a vein. When there's also a clot, it's more accurately called superficial vein thrombosis: a vein located just under the skin becomes inflamed and partially blocked.
It often appears over a pre-existing varicose vein, because blood flows less well through those dilated veins. It can also appear after a bump, an intravenous line, or periods of immobility.
How to recognize it
Superficial phlebitis usually presents a fairly characteristic picture:
- A hard, palpable cord under the skin, following the path of the vein.
- Redness, warmth, and pain in that area.
- The surrounding skin may be somewhat swollen and tender to the touch.
Unlike deep thrombosis, here the inflammation can be seen and felt, because the vein is near the surface.
Phlebitis versus deep thrombosis
| Phlebitis (superficial) | Deep thrombosis (DVT) | |
|---|---|---|
| Affected vein | Superficial, under the skin | Deep, inside the leg |
| What you notice | Red, hard, visible cord | Swelling and pain throughout the leg |
| Main risk | Lower; can extend to the deep vein | Pulmonary embolism |
These aren't watertight compartments: extensive phlebitis can progress into the deep system, especially when it affects the saphenous vein near the groin. That's why it should be evaluated and, if there's any doubt, deep vein thrombosis should be ruled out.
Phlebitis is usually benign, but I pay close attention to where it is. Extensive phlebitis, or phlebitis near the saphenofemoral or saphenopopliteal junction, carries a higher risk of progressing into the deep venous system and changes the treatment.
Treatment
It depends on the extent and location. It usually includes local measures (anti-inflammatories), compression stockings, and low-dose anticoagulation. Complete bed rest isn't recommended. In more extensive cases or those close to the deep system, anticoagulation is usually at full dose, similar to deep vein thrombosis. Doppler ultrasound is an essential tool for mapping its extent.
When phlebitis repeatedly appears over varicose veins, it's worth investigating and treating the underlying venous insufficiency to prevent recurrence.
In summary
Phlebitis, or superficial vein thrombosis, feels like a red, hard, painful cord under the skin, and it's usually less serious than deep thrombosis. Even so, it deserves evaluation, especially if it's near the groin or the popliteal fossae, or if it recurs over varicose veins. With proper treatment it improves, and treating the underlying varicose veins helps prevent it from coming back.