Lemierre syndrome
Formal Definition
Lemierre syndrome — a rare but classic post-pharyngitis septic thrombophlebitis of the internal jugular vein caused by Fusobacterium necrophorum, typically affecting young adults shortly after an episode of pharyngitis; characterized by the triad of (1) recent oropharyngeal infection, (2) internal jugular vein septic thrombophlebitis with bacteremia, and (3) distant septic emboli (most commonly pulmonary, but also hepatic, joint, cerebral); presents 4-8 days after initial sore throat with neck pain, fever, neck swelling/stiffness, bacteremia, and progressive pulmonary infiltrates.
How It's Used on the Ward
"Lemierre's" — the dramatic but rare complication of a sore throat caused by the bacterium Fusobacterium necrophorum seeding the internal jugular vein and showering septic emboli to the lungs; almost forgotten in the antibiotic era because pharyngitis is treated with antibiotics, but still occurs in patients who didn't seek care; the textbook triad is sore throat → internal jugular thrombosis → pulmonary emboli.
Example
""22-year-old college student with 5 days of sore throat treated with supportive care only, now 3 days of worsening fever, right neck pain and swelling, and dyspnea. Exam: T 39.4°C, tender right anterior cervical chain, no fluctuance. Labs: WBC 18.2, CRP 220. Blood cultures: Fusobacterium necrophorum. CT neck with contrast: right internal jugular vein thrombosis. CT chest: multiple bilateral peripheral pulmonary nodules with cavitation (septic emboli). Diagnosis: Lemierre syndrome. Started IV ampicillin-sulbactam + metronidazole, anticoagulation for the IJ thrombus, prolonged antibiotic course planned (4-6 weeks). Lung involvement monitored.""
Clinical Context
Pathophysiology: Fusobacterium necrophorum — anaerobic gram-negative rod that produces a lipopolysaccharide endotoxin and a leukocidin; colonizes the oropharynx normally but invades after mucosal disruption (acute pharyngitis); spreads to parapharyngeal space, invades the internal jugular vein wall, causes septic thrombophlebitis, bacteremia, and septic emboli. Diagnostic pitfalls: early presentation mimics common pharyngitis, then neck pain and fever develop; pulmonary involvement often signals the disease before IJ thrombosis is recognized. Imaging: CT or MRI neck with contrast to identify IJ thrombosis; CT chest for pulmonary emboli. Treatment: prolonged IV antibiotics with anaerobic coverage (ampicillin-sulbactam, ceftriaxone + metronidazole, piperacillin-tazobactam, or carbapenem); 4-6 weeks total therapy; anticoagulation for IJ thrombus is controversial but commonly used. Complications: septic emboli to lungs, liver, joints, brain; acute respiratory distress syndrome; cavernous sinus thrombosis; carotid artery involvement; mortality historically 90% pre-antibiotics, now <5% with treatment.