Microbiology · Year 2 · from Microbiology
Case 1: Lemierre Syndrome
Presentation
A previously healthy 19-year-old college student presents with 5 days of severe sore throat, fever, and neck pain. He was seen at an urgent care clinic 3 days ago and was diagnosed with pharyngitis. Today he developed rigors, pleuritic chest pain, and cough. Examination reveals fever of 40.1°C, tachycardia, tenderness and swelling along the left sternocleidomastoid muscle, and decreased breath sounds at the right base. CT scan of the neck shows thrombosis of the left internal jugular vein with surrounding inflammation. CT chest reveals multiple bilateral peripheral nodular infiltrates, some with cavitation.
Clinical Image
CT scan of the neck demonstrating thrombosis of the internal jugular vein (arrow) with surrounding soft tissue inflammation, characteristic of Lemierre syndrome.
Image Source: Lecture image - Fusobacterium necrophorum infection
Questions
- What is the diagnosis and the most likely causative organism?
- Describe the typical pathophysiology and clinical progression of this syndrome.
- What is the significance of the pulmonary findings on CT chest?
- What is the appropriate treatment for this condition?
Answers
- Diagnosis and organism: This is Lemierre syndrome, most commonly caused by Fusobacterium necrophorum, a gram-negative obligate anaerobe that is part of normal oropharyngeal flora. Lemierre syndrome, also called "postanginal sepsis," is characterized by the triad of pharyngitis, internal jugular vein thrombophlebitis, and septic emboli (most commonly to the lungs). It typically affects previously healthy young adults.
- Pathophysiology and progression: The syndrome begins with pharyngitis or peritonsillar infection that extends to involve the lateral pharyngeal space and subsequently the internal jugular vein, causing septic thrombophlebitis. From this infected thrombus, septic emboli disseminate hematogenously, most commonly to the lungs (causing septic pulmonary emboli and abscesses) but also potentially to joints, bones, liver, and other organs. The typical patient presents with persistent sore throat, neck pain and swelling, rigors, and respiratory symptoms.
- Pulmonary findings significance: The multiple bilateral peripheral nodular infiltrates with cavitation represent septic pulmonary emboli. These are characteristic of Lemierre syndrome and result from hematogenous seeding from the infected internal jugular vein thrombus. The peripheral distribution and tendency to cavitate distinguish them from typical community-acquired pneumonia. Empyema and lung abscess may develop. The pulmonary involvement is responsible for significant morbidity and is often the reason patients seek medical attention.
- Treatment: Treatment includes prolonged intravenous antibiotics covering anaerobes and streptococci, typically for 4-6 weeks. Appropriate regimens include beta-lactam/beta-lactamase inhibitor combinations (ampicillin-sulbactam, piperacillin-tazobactam) or carbapenems, often combined with metronidazole for enhanced anaerobic coverage. The role of anticoagulation remains controversial, with some evidence supporting its use in extensive thrombosis. Surgical drainage of abscesses or empyema may be required. Internal jugular vein ligation is rarely necessary.