[Clinical case of the month. An unusual sepsis].

Lemierre's syndrome is a rare, but significant pathology to recognize. It most often affects young patients in good health; a late diagnosis can be fatal. It consists in an anaerobic septicemia (usually, Fusobacterium necrophorum) originating from a suppurative thrombophlebitis of the internal jugular vein. Infection occurs during a common sore throat and spreads by contiguity. The clinical presentation is a sepsis with pulmonary embolisations, but other sites of dissemination can also occur. Treatment consists of prolonged intravenous antibiotherapy associated with supportive therapy, if needed. Anticoagulation remains controversial. The outcome is favorable in most cases provided diagnosis and treatment are early; mortality however remains significant, around 5%.