Lemierre syndrome is infection extending to soft tissue of neck

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This patient has Lemierre syndrome, also termed postanginal sepsis or septic thrombophlebitis of the internal jugular vein. Proper management requires radiologic visualization of the source of the infection in the neck and antibiotics including coverage for mouth anaerobes (choice D is correct).

Lemierre syndrome is a relatively rare infectious complication of pharyngitis, seen most often in otherwise healthy young adults. It is usually caused by species of normal mouth flora, with the most common pathogen isolated being the anaerobe Fusobacterium necrophorum. This infection usually follows a case of typical pharyngitis with a lag time of 1 to 3 weeks.  Common clinical findings are antecedent throat pain, fever, rigors, dysphagia, and trismus.  When septic embolization occurs, patients often note cough, dyspnea, pleurisy, and hemoptysis. In as many as one-half of patients, throat and neck symptoms and findings may largely resolve at the time pulmonary manifestations occur. Lung findings seen radiologically are most commonly multiple nodules that may cavitate. Empyema, lung abscesses, necrotizing mediastinitis, and pneumothoraces may also be seen. CT scan in this patient revealed abundant nodules with an area of pleural reaction correlating to his reported left-sided chest pain. After pulmonary involvement, joints are the next most common sites of metastatic infection. Less common sites of involvement are bone, liver, spleen, cardiac valves, and CNS.

Imaging of the neck allows confirmation of the diagnosis. In rare cases where infection extends into soft tissues of the neck or infection spreads to the mediastinum, surgery may be required. In this patient, involvement of the left internal jugular vein was confirmed by CT scan (Figure 2, arrow). Ultrasound has also been used to assess blood flow in the neck in this context. Empiric antibiotic therapy should be started while throat and blood cultures are pending to guide specific antibiotic treatment.  Recommended regimens include piperacillin-tazobactam; carbapenem (eg, imipenem, meropenem, or ertapenem); or ceftriaxone plus metronidazole. Ceftriaxone alone would not be sufficient because of inadequate anaerobic coverage by this agent. Most experts recommend a prolonged antibiotic course of 4 weeks, with 2 weeks of initial parenteral therapy. Blood cultures and imaging of involved sites should be used to confirm resolution. Anticoagulation is not usually recommended. 

Other infections and some malignancies may give a radiologic appearance of multiple nodules arising from hematogenous spread. Staphylococcal septic embolization can occur from endocarditis or from indwelling catheters; however, this patient did not fit this picture, and endocarditis was adequately excluded by transthoracic echocardiogram. Performing a transesophageal echocardiogram and adding vancomycin would not be warranted (choice A is incorrect). On rare occasions, vancomycin will be needed for treatment of Lemierre syndrome if culture data so guides therapy. Fungal infection would be inconsistent with this patient's history (choice B is incorrect). Although thyroid malignancy can metastasize to lung(s) and manifest as multiple nodules, this patient has no risk factors for thyroid cancer, and the clinical presentation strongly suggests underlying infection. Thyroid function tests alone would not assist greatly in making a diagnosis of metastatic thyroid cancer, although thyroglobulin levels are helpful in determining if ablation therapy has been successful in the treatment of this cancer (choice C is incorrect).