Phlebitis is a medical condition characterized by inflammation of a vein, most commonly occurring in the legs. The term is often used interchangeably with “thrombophlebitis,” which specifies that the inflammation is caused by a thrombus, or blood clot, forming inside the vein. Phlebitis is categorized into three primary types based on the affected vein’s location and the presence of infection. Understanding these distinctions is important because the severity and necessary treatment vary significantly.
Superficial Phlebitis
This form of phlebitis affects veins near the skin’s surface, making it the most visible and common type. Inflammation typically results from a blood clot forming in superficial veins, such as the saphenous veins in the leg. Common causes include minor trauma, varicose veins, or irritation from an intravenous (IV) line insertion.
Symptoms are localized along the path of the affected vein. The area often appears red, feels warm, and is tender or painful to the touch. The vein may feel firm or cord-like beneath the skin due to the clotted and inflamed vessel. While uncomfortable, this type of phlebitis is generally considered less serious than deep vein involvement and often resolves with conservative treatment.
Deep Vein Thrombosis
Deep Vein Thrombosis (DVT) involves the formation of a blood clot within major veins, usually those deep within the leg or thigh muscles. DVT is a significant medical concern because of the high risk of pulmonary embolism (PE). This occurs if a part of the clot breaks off and travels through the bloodstream to the lungs, blocking blood flow.
The risk of developing DVT is related to factors that slow blood flow, damage the vein lining, or increase the blood’s tendency to clot. These factors align with Virchow’s Triad, including prolonged immobility, such as during long flights or after surgery, and conditions that increase blood clotting, like certain genetic disorders or cancer. Symptoms of DVT may include swelling of the affected limb, pain, skin discoloration, and warmth in the area. Many people experience no symptoms at all, meaning the condition may not be diagnosed until a complication like a pulmonary embolism occurs, which requires immediate medical attention.
Septic Phlebitis
Septic phlebitis is a less common but serious type where the vein wall and the associated blood clot become infected with bacteria. This condition often develops as a complication of a medical procedure, particularly when a foreign object like an intravenous catheter or central line is in place. Bacteria can be introduced during line placement or colonize the device afterward, spreading to the vein.
The presence of bacteria within the thrombus can lead to a systemic infection, potentially resulting in sepsis. Symptoms are similar to other types of phlebitis, such as localized pain and swelling, but are accompanied by systemic signs of infection like fever and chills. Treatment requires aggressively targeting the bacterial infection with antibiotics while managing the clot. In many cases, the infected catheter or central line must be removed to clear the source of contamination.
Confirming the Diagnosis and Initial Treatment Steps
When phlebitis is suspected, diagnosis is most often achieved through non-invasive imaging. The primary tool is a venous duplex ultrasound, which uses sound waves to visualize blood flow and identify a clot within the vein. This test helps determine the exact location and extent of the thrombus, which is important for distinguishing between superficial and deep involvement.
A blood test called a D-dimer assay may also be used, which measures a protein fragment elevated when a blood clot is present. While a positive D-dimer result is not specific to phlebitis, a negative result can help rule out DVT. Once the diagnosis and type are confirmed, initial treatment steps generally focus on reducing inflammation and discomfort.
Measures include elevating the affected limb and applying warm compresses to the tender area. Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) may be recommended to relieve pain and swelling. Compression stockings are often used to improve blood flow and prevent blood from pooling in the veins. The specific medical treatment is guided by the type of phlebitis, such as prescribing blood thinners for deep vein clots or antibiotics for septic phlebitis.