Suppurative thrombophlebitis overview

# Overview
Suppurative thrombophlebitis is a life threatening condition characterized by the presence of venous thrombosis, inflammation, and bacteremia. Suppurative thrombophlebitis usually occurs in the setting of an intravascular catheter, and is suspected in patients with radiographic evidence of thrombosis and persistent bacteremia after 72 hours of appropriate antimicrobial therapy.  Suppurative thrombophlebitis may be classified into many subtypes according to the vein involved.  Subtypes of suppurative thrombophlebitis include peripheral vein, internal jugular vein (Lemierre's syndrome), vena caval, portal vein, and pelvic vein suppurative thrombophlebitis. The majority of cases of suppurative thrombophlebitis are caused by bacteria. Common causes of peripheral vein thrombophlebitis include Staphylococcus aureus (most common cause), streptococci, and Enterobacteriaceae. The most common cause of Lemierre's syndrome is Fusobacterium necrophorum. Peripheral suppurative thrombophlebitis should be differentiated from cellulitis and deep venous thrombosis; while abdominal and pelvic vein suppurative thrombophlebitis must be differentiated from septic abortion, acute appendicitis, cholangitis, and other genitourinary infections.  Lemierre disease must be differentiated from peritonsillar abscess, pharyngitis, and soft tissue neck abscess. Common risk factors in the development of suppurative thrombophlebitis are the use of intravenous catheters, intravenous drug use, hypercoagulable states, burns, pharyngitis, and tonsillitis. Lemierres syndrome is now a rare condition with an incidence of 0.36 cases per 100,000 individuals annually.  Extremes of age also predispose the occurrence of septic thrombophlebitis, due to the increased risk of infections by catheters. If left untreated, suppurative thrombophlebitis may metastasize to different organs. Untreated suppurative thrombophlebitis is associated with a high mortality rate.. The most common complication of suppurative thrombophlebitis is metastatic septic foci that spread to different organs of the body.  Common complications of suppurative thrombophlebitis are septic shock, sustained sepsis, infective endocarditis, septic emboli to the central nervous system, and septic pulmonary emboli. When obtaining a history from a patient with suspected suppurative thrombophlebitis, specific areas of focus include a history of an intravenous catheter, a phlebotomy attempt, and intravenous injections.  Common symptoms of superficial vein thrombophlebitis include fever, erythema, and tenderness and purulent drainage at the site of the involved vessel. Symptoms of Lemierre syndrome include fever, rigors, localized neck pain, and erythema, tenderness, swelling, and induration overlying the jugular vein. Common physical examination findings in patients with suppurative thrombophlebitis include fever, tenderness and purulent drainage at the site of the involved vessel, erythema, nausea, vomiting, and fatigue. The mainstay of therapy for suppurative thrombophlebitis is antimicrobial therapy. Surgical treatment of suppurative thrombophlebitis is considered in cases that do not respond to antimicrobial therapy.  Incision and drainage, or excision of the affected vein and its tributaries may be considered.

# Historical Perspective
Pelvic thrombophlebitis was discovered by the end of the 19th century when von Recklinhausen described an entity in which pelvic infection was characterized by thrombosis of one or both ovarian veins while the remaining pelvis was normal, proposing surgical excision as the therapeutic approach. Sepsis following from a throat infection was first described by Scottmuller in 1918.  In 1936, Andre Lemierre published a series of 20 cases where throat infections were followed by identified anaerobic septicemia, of whom 18 patients died.  This disease came to be known as Lemierre's syndrome.

# Classification
Suppurative thrombophlebitis may be classified into many subtypes according to the vein involved.  Subtypes of suppurative thrombophlebitis include peripheral vein, internal jugular vein, vena caval, portal vein, and pelvic vein suppurative thrombophlebitis.

# Pathophysiology
The pathophysiology of suppurative thrombophlebitis depends on the subtype. Lemierre's syndrome is initiated by an infection of the head and neck region.  During the primary infection, F. necrophorum colonizes the infection site and the infection spreads to the parapharyngeal space. The bacteria then invade the peritonsillar blood vessels where they can spread to the internal jugular vein. In this vein, the bacteria cause the formation of a thrombus containing these bacteria. The pathogenesis of pelvic vein suppurative thrombophlebitis is thought to include injury to the intima of the pelvic vein caused by a spreading uterine infection, bacteremia, and endotoxins, which can also occur secondary to the trauma of delivery or surgery. Pylephlebitis is due to an abdominal infection that drains into the portal venous system.  The most commonly isolated organism is Bacteroides fragilis, which facilitates coagulation via the capsular and surface components. Capsular polysaccharides activate macrophages therefore initiating the clotting cascade while the surface component accelerates fibrin cross-linking.

# Causes
The majority of cases of suppurative thrombophlebitis are caused by bacteria. Common causes of peripheral vein thrombophlebitis include Staphylococcus aureus (most common cause), streptococci, and Enterobacteriaceae. The most common cause of Lemierre syndrome is Fusobacterium necrophorum.

# Differentiating Suppurative thrombophlebitis from other Diseases
Peripheral suppurative thrombophlebitis should be differentiated from cellulitis and deep venous thrombosis; while abdominal and pelvic vein suppurative thrombophlebitis must be differentiated from septic abortion, acute appendicitis, cholangitis, and other genitourinary infections.  Lemierre disease must be differentiated from peritonsillar abscess, pharyngitis, and soft tissue neck abscess.

# Risk Factors
Common risk factors in the development of suppurative thrombophlebitis are the use of intravenous catheters, intravenous drug use, hypercoagulable states, burns, pharyngitis, and tonsillitis.

# Epidemiology and Demographics
Lemierres syndrome is now a rare condition with an incidence of 0.36 cases per 100,000 individuals annually. Lemierres syndrome is primarily a disease of previously healthy children, adolescents, and young adults.  Extremes of age also predispose the occurrence of septic thrombophlebitis, due to the increased risk of infections by catheters.  Pylephlebitis is slightly more common in males.

# Natural History, Complications and Prognosis
If left untreated, suppurative thrombophlebitis may metastasize to different organs. Untreated suppurative thrombophlebitis is associated with a high mortality rate.. The most common complication of suppurative thrombophlebitis is metastatic septic foci that spread to different organs of the body.  Common complications of suppurative thrombophlebitis are septic shock, sustained sepsis, infective endocarditis, septic emboli to the central nervous system, and septic pulmonary emboli.  Septic thrombophlebitis of the intracranial dural sinuses has a very high mortality rate, compared to pelvic and jugular thrombophlebitis.  Lemierre's syndrome has a documented mortality rate of 6.4%.

# History and Symptoms
When obtaining a history from a patient with suspected suppurative thrombophlebitis, specific areas of focus include a history of an intravenous catheter, a phlebotomy attempt, and intravenous injections.  Common symptoms of superficial vein thrombophlebitis include fever, erythema, and tenderness and purulent drainage at the site of the involved vessel. Symptoms of Lemierre syndrome include fever, rigors, localized neck pain, and erythema, tenderness, swelling, and induration overlying the jugular vein.

# Physical Examination
Common physical examination findings in patients with suppurative thrombophlebitis include fever, tenderness and purulent drainage at the site of the involved vessel, erythema, nausea, vomiting, and fatigue.

# Laboratory Findings
The majority of patients with suppurative thrombophlebitis have persistent positive blood cultures despite adequate antimicrobial therapy for 3 days.

# Medical Therapy
The mainstay of therapy for suppurative thrombophlebitis is antimicrobial therapy.  Empiric therapy includes anti-staphylococcal antibiotics plus antibiotics with coverage against enterobacteriaceae. The benefit of pharmacologic anticoagulation is uncertain in suppurative thrombophlebitis and is not routinely recommended.

# Surgery
Surgical treatment of suppurative thrombophlebitis is considered in cases that do not respond to antimicrobial therapy.  Incision and drainage, or excision of the affected vein and its tributaries may be considered.