Why am I posting about this “zebra?” Well, Fusobacterium necrophorum infections may be more common in adolescents and young adults than previously suspected. There also seems to be a rise in the incidence of new diagnoses – and we are not sure why. Finally, it can make patients very sick, and it presents first like garden variety pharyngitis (think strep and mono). It should always be on your radar in the ill adolescent with a history of sore throat, fever and neck pain.

Lemierre’s syndrome is characterized by:

1. A recent oropharyngeal infection

2. Internal jugular venous thrombosis

3. Isolation of anaerobic pathogens (classically Fusobacterium necrophorum)

Usual first clinical presentation of Lemierre syndrome via Karkos et al. Laryngoscope

The classic cause is Fusobacterium necrophorum , a gram-negative anaerobe that is part of the normal oral, GI and female GU flora. There is a slight fame to male predominance, and though it can present at any age it is most common in the 2nd and third decade of life. This is likely due to the maturation and development of lymph tissue along the neck. It is felt to be pathogenic because of the toxins it produces (see Golpe et al. for more)which cause destruction of blood cells and hemagglutination. First, a patient gets a sore throat. This is often followed by fever, and then the patient becomes septicemic – and infectious thrombi seed the jugular veins – causing a purulent thrombophlebitis. The vessels in the lateral pharyngeal space are adjacent to the peritonsillar space – and the organism usually spreads in less than a week after the initial pharyngitis develops. Patients go from having a sore throat to having neck tenderness and swelling. The dream of all thrombi is to become emboli, and those in Lemierre’s are no different. The metastatic infectious emboli in Lemierre’s shower the body, and cause secondary abscesses in the lung, bone and other organs.

It is important to remember that though most cases arise form a preceding pharyngeal infection it can come from anywhere in the ENT zone. According to a systemic review from Karkos et al. in Laryngoscope (seriously, that is a great journal name – much better than speculum) the most common sources for infection are:

Source of Infection for Lemierre’s Syndrome via Karkos et al. Laryngoscope

Diagnosis is aided by clinical suspicion and requires imaging studies such as ultrasound or CT with contrast of the next. See the right column for representative images. Contrast CT is the most definitive, and it will distended jugular veins with wall enhancement, filling defects inside the vessel lumen and adjacent soft tissue inflammation. Ultrasound shows internal jugular thrombosis. You will also need a blood culture that isolates the causative pathogen – an anaerobic one at that if you hope to catch F necrophorum. 

Treatment is with broad spectrum antibiotics – though the optimal regimen is not known. F necrophorum is an obligate anaerobe, so drugs like Clindamycin make the most sense. Check with your microbiology/Infectious Disease local experts first – but a sample initial regimen for the patient with suspected Lemierre’s could include IV penicillin and metronidazole or monotherapy with clindamycin for 2–6 weeks. See Hagelskjaer Kristensen et al. for more. Again, and I can’t drive this home enough, if you are suspicious about Lemierre’s please OBTAIN AN ANAEROBIC BLOOD CULTURE!