Introduction: Lemierre's syndrome is a septic thromboembolic complication of an oropharyngeal or neck infection, primarily caused by Fusobacterium species. Although it usually affects young healthy patients, some case reports describe this syndrome in older population.Methods: A case report and a systematic review of the literature were conducted to investigate the late onset of Lemierre's syndrome. Forty-one articles were selected for the qualitative analysis, 39 for the quantitative analysis.Results: The average age of the study population was 52 years old. Diabetes mellitus and upper gastro-intestinal malignancy, common comorbidities in the study population, might play a role in the development of late-onset Lemierre's syndrome. Empiric antibiotic treatment should cover Fusobacterium and Streptococcus species both, which may cooperate to induce purulent disease. Reported unfavourable outcome was more than expected.Conclusion: Lemierre's syndrome in adulthood may differ from the usual version. This disease may further pass unrecognized, if presented out of the expected age range. Nevertheless, early diagnosis and prompt treatment are a requisite to prevent morbidity and mortality, which may be higher in this older population.
Keywords: Fusobacterium necrophorum; Infectious disease; Lancefield group F Streptococcus; Lemierre’s syndrome; internal jugular vein thrombosis.