What is Lemierre syndrome?

What is Lemierre Syndrome

Lemierre syndrome is a rare but life-threatening condition characterized by septic thrombophlebitis of the internal jugular vein (or other head and neck veins) with septic emboli, occurring as a complication of oropharyngeal infection, most commonly caused by Fusobacterium necrophorum. 1, 2

Pathophysiology and Causative Organisms

• Fusobacterium necrophorum is the predominant pathogen, implicated in approximately 10-20% of endemic pharyngitis cases in adolescents and serving as the primary cause of Lemierre syndrome 3, 1
• Other causative organisms include Fusobacterium nucleatum, anaerobic streptococci, staphylococci, and Klebsiella pneumoniae 4
• The infection typically originates from pharyngitis or tonsillitis in over 85% of cases, progressing to septic thrombophlebitis of the internal jugular vein (classically) or other head and neck veins 3, 4
• The syndrome can manifest with thrombosis at various vascular sites beyond the internal jugular vein, including the azygos vein, supporting a broader conceptualization of the disease 5

Patient Population and Clinical Context

• The syndrome predominantly affects previously healthy adolescents and young adults 1, 2, 6
• The incidence has increased over the past decade, likely related to decreased antibiotic prescribing for upper respiratory tract infections through antibiotic stewardship programs 4
• Despite modern treatment, the condition carries considerable rates of in-hospital complications, death, and long-term sequelae 2, 7

Clinical Presentation

Patients present with severe pharyngitis followed by persistent fever, rigors, night sweats, tender lymph nodes, neck pain/swelling, and signs of sepsis 1, 3. Key features include:

• Initial pharyngitis or tonsillitis that progresses to persistent pyrexia and systemic sepsis several days after the initial infection 6
• Neck tenderness or swelling indicating internal jugular vein thrombophlebitis 3
• Respiratory symptoms from septic pulmonary emboli, which represent the most common metastatic infection site 4, 5
• Septic emboli can seed to distant sites including lungs, joints, skin, liver, spleen, brain, and vertebral bodies 6, 5

When to Suspect Lemierre Syndrome

Clinicians should maintain a high index of suspicion in adolescent and young adult patients presenting with unusually severe pharyngitis, particularly when accompanied by difficulty swallowing, drooling, neck tenderness, or swelling 3, 1. Specific red flags include:

• Persistent fever and septic syndrome several days after initial pharyngitis 4, 6
• Neck pain with systemic signs of sepsis 4
• Respiratory symptoms suggesting septic emboli 5
• Thrombocytopenia, which is consistent with the thrombogenic properties of F. necrophorum 5

Complications and Prognosis

• The condition can be fatal or cause disabling sequelae despite treatment 7
• Common complications include thrombus progression, new peripheral septic embolization, and multi-organ failure requiring intensive care support 7, 6
• Metastatic infections include pneumonia, pleural empyema, vertebral osteomyelitis, and septic arthritis 4, 5

Diagnostic Urgency

Urgent diagnosis and treatment of Lemierre syndrome is necessary to preclude complications and death 3. The condition requires:

• Thorough radiological evaluation in patients with persistent oropharyngeal symptoms and unexpected systemic manifestations, even when classic internal jugular vein thrombosis is absent 5
• Blood cultures to identify F. necrophorum bacteremia 5
• Imaging to detect internal jugular vein thrombophlebitis and septic emboli 3

Management Principles

• Prolonged antimicrobial therapy for 3-6 weeks is the mainstay of treatment, typically including metronidazole and β-lactam antibiotics 4, 7
• Anticoagulation is often used but remains controversial without clear evidence-based guidelines 7
• Surgical intervention may be necessary for peripheral septic lesions 7
• Admission to intensive care is common due to multi-organ involvement 6