Discussion
Lemierre’s syndrome (LS) is a rare complication of infections of the head and neck, with a reported incidence of one case per million people per year.1 Once common during the “pre-antibiotic era”, LS had decreased in incidence for decades but has been increasing in incidence since the 1990s. This is thought to be secondary to better antimicrobial stewardship and decreased use of antimicrobial therapy for individuals presenting with pharyngitis.1 Disease is attributed to infections of the palatine tonsils and peritonsillar tissue in 87% of cases and infections of the pharynx, parotid glands, sinuses, mastoids, middle ears, and teeth/gums in the remaining 13% of cases.2 Males and females are thought to be equally affected.3 LS has been reported in individuals aged 2 months to 78 years although it is most commonly reported among previously healthy adolescents and young adults.2,3
Lemierre’s syndrome is thought to originate with primary infection in the head or neck.4 This is followed by local spread of the infection through the soft tissues of the neck resulting in thrombophlebitis of the internal jugular vein. Finally, dissemination of infection through septic emboli occurs. Sites of infection include the lungs in up to 80% of cases and bones and joints in up to 27% of cases.1-4 Additional sites of infection include cardiovascular structures, skin and muscles, central nervous system, abdominal organs including liver and spleen, and kidneys. Pulmonary involvement has included septic emboli, abscess formation, necrotizing pneumonia, empyema, pneumothorax, pulmonary embolism, and acute respiratory distress syndrome. LS is most often caused byFusobacterium necrophorum , part of the normal flora of the pharynx, which may account for up to 85% of cases. Other causes include additional Fusobacterium species, anaerobes includingBacteroides , Peptococcus , and Peptostreptococcusspecies, and aerobes including Streptococcus , andStaphylococcus species, and others. Polymicrobial infections have been reported in up to 30% of cases.2 Significant morbidity has been reported as a result of delayed diagnosis. Mortality rates have previously been reported as 4-18%; however, more recent reviews suggest a lower rate.3,5
Individuals with LS often present 4 to 12 days after the initiating oral pharyngeal infection, which may have resolved by the time of presentation. Symptoms include high fever (up to 80% of cases), gastrointestinal complaints (50%), pharyngitis with cervical adenopathy or neck pain/swelling, myalgia/arthralgia, rigors, and respiratory symptoms, which may include cough or dyspnea.1,2,5Additional symptoms may be secondary to organ system dysfunction caused by septic emboli. Diagnosis is often made based on Doppler ultrasound or computed tomography imaging of the head and neck or the growth ofFusobacterium or other bacteria from blood or abscess cultures.
Therapy for LS typically involves long term, intravenous antibiotic therapy, surgical drainage of abscess sites, and anticoagulation.1-6 Metronidazole is often reported as standard therapy for LS. Other antibiotic considerations include carbapenems or penicillin/beta-lactamase inhibitor combinations, which may provide broader coverage for polymicrobial infections. Duration of therapy is often 4 to 6 weeks to allow for adequate penetration of thrombi as well as treatment of secondary problems such as osteomyelitis. The role of anticoagulation therapy is more controversial. Some data suggest that the use of anticoagulation hastens overall response while others indicate adequate clinical response without additional therapy.
Lemierre’s syndrome is a rare disorder of the head and neck that may be associated with significant morbidity and mortality if diagnosis and treatment are delayed. Hence, a high index of suspicion must be maintained in order to identify children with LS. Pediatric pulmonologists will most likely encounter LS in patients hospitalized with prolonged fever and multiple septic pulmonary emboli. LS must be considered as part of the differential diagnosis for any child with multiple cavitary nodules identified on chest CT imaging. This is particularly true if there is a history of proceeding oral pharyngeal infection or acute signs and symptoms suggesting pathology in the head and neck. The growth of Fusobacterium species from blood culture or abscesses should also suggest the possibility of LS. If LS is suspected, Doppler ultrasound examination of the neck and possible CT imaging of the head and neck should be obtained. Therapy should include long-term intravenous antibiotics directed at the treatment of specific organisms recovered. Adjuvant therapy with surgical incision and drainage of abscesses or anticoagulation therapy may be necessary in some cases.