Lemierre’s Syndrome: An Atypical Case of Fusobacterium necrophorum Bacteraemia in the Absence of Internal Jugular Vein Thrombosis

Lemierre's syndrome primarily affects healthy adolescents and young adults as a complication of oropharyngeal infection, most commonly pharyngitis or peritonsillar abscess. Fusobacterium necrophorum is the principal pathogen, and the infection presents with classic symptoms including fever, sore throat, and neck tenderness. However, atypical presentations can pose diagnostic challenges. This report discusses a patient in her early 60s, contrary to the typical demographic, who presented with a one-week history of varied symptoms including sore throat, pleuritic chest pain, and haemoptysis. Examination revealed mild neck tenderness and lung crepitations. Laboratory tests indicated leucocytosis, thrombocytopenia, and elevated C-reactive protein (CRP). Imaging revealed pulmonary infiltrates with cavitation. F. necrophorum was detected in blood culture, promoting a CT scan of the neck, which confirmed soft tissue swelling and a small peritonsillar collection, leading to the diagnosis of Lemierre's syndrome. The classical feature of jugular vein thrombus was absent, further underscoring the atypical nature of this case. The patient received immediate initiation of intravenous antibiotics, piperacillin/tazobactam, followed by meropenem. This was complemented by a carefully tailored 21-day intravenous course, followed by an eight-week regimen of oral antibiotics consisting of amoxicillin and metronidazole. The patient demonstrated significant clinical improvement in pulmonary complications. Follow-up imaging showed minor residual changes, and the patient remained asymptomatic. Lemierre's syndrome presents a diagnostic challenge due to diverse clinical manifestations. Key diagnostic markers include deep neck infections, septicemia, and metastatic infections. Timely utilization of diagnostic tools, such as blood cultures and imaging, aid in confirmation. Early diagnosis is crucial for prompt treatment and prevention of complications. This case emphasizes the importance of maintaining a high index of suspicion for Lemierre's syndrome, especially in atypical presentations. Increased awareness among healthcare providers is vital for timely diagnosis and optimal patient outcomes.