Phlebitis

Phlebitis is inflammation of a vein. It can be superficial or associated with thrombosis (thrombophlebitis). It most commonly affects superficial veins of the legs but can occur in any venous territory, and it may be related to intravenous therapy, injections, or local trauma.

Superficial phlebitis presents with localized pain, redness, warmth, and tenderness along a visibly inflamed vein. A firm, tender cord may be felt under the skin. When a clot is present (thrombophlebitis), swelling can extend beyond the area of the inflamed segment. Fever is more likely with infection (septic phlebitis).

Causes include mechanical irritation from intravenous catheters, trauma, varicose veins, infections, chemical irritation from infusates, and autoimmune or inflammatory conditions. Risk factors are recent IV therapy, prolonged catheterization, age, obesity, pregnancy, smoking, and congenital or acquired hypercoagulable states.

Diagnosis relies on history and exam, supported by imaging such as duplex ultrasonography to detect thrombosis in the affected vein. Blood tests may show inflammatory markers; D-dimer testing is more helpful in assessing deep vein thrombosis when clinically indicated. Blood cultures are used if infection is suspected.

Treatment aims to relieve symptoms and prevent complications. Uncomplicated superficial phlebitis is usually managed with NSAIDs or acetaminophen, warm compresses, leg elevation, and activity modification; removing or replacing an irritant such as an IV catheter is important. If a clot forms or infection is present, antibiotics and anticoagulation may be required.

Prognosis is generally favorable for superficial phlebitis, with most cases resolving within one to three weeks. Deep or septic phlebitis carries higher risks, including extension of thrombosis and, rarely, pulmonary embolism, so treatment and monitoring are guided by severity and underlying causes. Prevention focuses on proper venous access care, early mobilization, and management of varicose veins.