Lemierre syndrome: A potentially lethal form of sore throat caused by the bacterium Fusobacterium necrophorum, a common inhabitant of the mouth. This disease vanished with the advent of antibiotics but then returned decades later. It has been called the "forgotten disease."
Lemierre syndrome develops most often after a strep sore throat has created a peritonsillar abscess, a crater filled with pus and bacteria near the tonsils. Deep in the abscess, anaerobic bacteria (microbes that do not require oxygen) like Fusobacterium necrophorum can flourish. The bacteria penetrate from the abscess into the neighboring jugular vein in the neck and there they cause an infected clot (thrombosis) to form, from which bacteria are seeded throughout the body by the bloodstream (bacteremia). Pieces of the infected clot break off and travel to the lungs as emboli blocking branches of the pulmonary artery bringing the heart's blood to the lungs. This causes shortness of breath, chest pain and severe pneumonia.
The keys to survival with Lemierre syndrome are prompt recognition of the disease, immediate use of antibiotics (to which the bacterium is responsive), and drainage of abscesses. Even with prompt appropriate therapy, the mortality (death) rate is 4 to 12%.
The syndrome was first described by A. Lemierre in the English medical journal The Lancet in 1936.