Case Report: An Unusual Case of Lemierre's Syndrome Presenting as Influenza B-Induced Myositis Complicated by Streptococcus intermedius Infection.

Lemierre's syndrome (LS) is a rare and severe complication primarily associated with the bacteria Fusobacterium necrophorum and characterized by an oropharyngeal infection leading to bacteremia and septic thrombophlebitis. We present a case of an 89-year-old patient with a history of hypertension who initially presented with type B influenza infection and neck pain. She subsequently developed a neck abscess with thrombosis of the internal jugular vein. We believe this to be the first reported case in the literature of LS secondary to Streptococcus intermedius presenting after infection with type B influenza. As more atypical LS cases emerge, it is becoming increasingly clear that this condition can manifest in a number of ways. This unique case highlights the importance of considering LS as a differential diagnosis for patients of all ages presenting with neck pain and Streptococcus intermedius infection.