Factors Affecting Patients with Concurrent Deep Neck Infection and Lemierre's Syndrome.

Deep neck infection (DNI) is a severe disease affecting the deep neck spaces, and is associated with an increased risk of airway obstruction. Lemierre's syndrome (LS) refers to septic thrombophlebitis of the internal jugular vein after pharyngeal infection, and is linked with high morbidity and mortality. Both diseases begin with an oropharyngeal infection, and concurrence is possible. However, no studies have examined the risk factors associated with co-existence of LS and DNI. Accordingly, this study examined a patient population to investigate the risk factors associated with concurrent DNI and LS. We examined data from a total of 592 patients with DNI who were hospitalized between May 2016 and January 2022. Among these patients, 14 had concurrent DNI and LS. The relevant clinical variables were assessed. In a univariate analysis, C-reactive protein (odds ratio (OR) = 1.004, 95% CI: 1.000-1.009, p = 0.045), involvement of multiple spaces (OR = 23.12, 95% CI: 3.003-178.7, p = 0.002), involvement of the carotid space (OR = 179.6, 95% CI: 22.90-1409, p < 0.001), involvement of the posterior cervical space (OR = 42.60, 95% CI: 12.45-145.6, p < 0.001) and Fusobacterium necrophorum ( F. necrophorum , OR = 288.0, 95% CI: 50.58-1639, p < 0.001) were significant risk factors for concurrent DNI and LS. In a multivariate analysis, involvement of the carotid space (OR = 94.37, 95% CI: 9.578-929.9, p < 0.001), that of the posterior cervical space (OR = 24.99, 95% CI: 2.888-216.3, p = 0.003), and F. necrophorum (OR = 156.6, 95% CI: 7.072-3469, p = 0.001) were significant independent risk factors for concurrent LS in patients with DNI. The length of hospitalization in patients with concurrent LS and DNI (27.57 ± 14.94 days) was significantly longer than that in patients with DNI alone (10.01 ± 8.26 days; p < 0.001), and the only pathogen found in significantly different levels between the two groups was F. necrophorum ( p < 0.001). Involvement of the carotid space, that of the posterior cervical space and F. necrophorum were independent risk factors for the concurrence of DNI and LS. Patients with concurrent LS and DNI had longer hospitalization periods than patients with DNI alone. Furthermore, F. necrophorum was the only pathogen found in significantly different levels in DNI patients with versus those without LS.