A 19-year-old man presents to the emergency department with a 2-day history of high fever, chills, and severe left-sided neck pain and swelling. He reports that he had a severe sore throat that began one week ago, which he thought was a simple cold, but the pain has now shifted to his neck. On physical examination, he is febrile to 103.1∘F and tachycardic. There is significant tenderness and cord-like induration along the left sternocleidomastoid muscle. Oropharyngeal exam shows resolving tonsillar erythema but no evidence of abscess. Lung auscultation reveals scattered crackles bilaterally. Laboratory studies show a white blood cell count of 18,000/mm3. A chest radiograph demonstrates multiple poorly defined nodular opacities in both lung fields.
Which of the following is the most likely diagnosis?
The correct answer is:
B) Lemierre syndrome
The patient is presenting with Lemierre syndrome, a rare but life-threatening condition characterized by septic thrombophlebitis of the internal jugular vein (IJV). It typically begins with a primary oropharyngeal infection like tonsillitis or pharyngitis that invades the lateral pharyngeal space. The most common causative organism is Fusobacterium necrophorum, an anaerobic component of the normal oral flora. The infection spreads to the IJV, leading to thrombosis and the subsequent release of septic emboli, most commonly to the lungs. The clinical hallmark is a cord-like sign (palpable thrombus in the IJV) in a patient with recent pharyngitis and respiratory symptoms.
Answer choice A: Infectious mononucleosis, is incorrect. While Epstein-Barr virus (EBV) infection causes severe pharyngitis and cervical lymphadenopathy, it does not typically cause IJV thrombosis or septic emboli to the lungs. It is more likely to present with significant fatigue, splenomegaly, and atypical lymphocytosis.
Answer choice C: Ludwig angina, is incorrect. Ludwig angina is a cellulitis of the submandibular space. While it involves neck swelling, the swelling is typically bilateral and woody in the submental/sublingual area, rather than localized along the sternocleidomastoid muscle. It does not typically cause septic pulmonary emboli.
Answer choice D: Parapharyngeal abscess, is incorrect. A parapharyngeal abscess can be a precursor to Lemierre syndrome, but once there is evidence of IJV involvement (the cord-like tenderness) and distant septic emboli (lung nodules), Lemierre syndrome is the more complete and specific diagnosis.
Answer choice E: Septic pulmonary embolism secondary to endocarditis, is incorrect. While right-sided infective endocarditis, which is most typically seen in IV drug users, causes septic pulmonary emboli, it would not explain the preceding severe pharyngitis or the localized, exquisitely tender induration along the internal jugular vein in the neck.
Key Learning Point
Lemierre syndrome is a triad of recent oropharyngeal infection, septic thrombophlebitis of the internal jugular vein, and metastatic septic emboli (usually pulmonary). It is most often caused by Fusobacterium necrophorum. Diagnosis is confirmed by CT of the neck with contrast showing an internal jugular vein filling defect. Management requires prolonged intravenous anaerobic coverage (e.g., ampicillin-sulbactam or carbapenems) and occasionally surgical drainage of the primary focus.
