Infectious causes of peripheral facial nerve palsy in children-a retrospective cohort study with long-term follow-up.

The aim of this study was to analyze the clinical and laboratory characteristics of children with peripheral facial nerve palsy (pFP) with a focus on identifying infectious etiology and long-term outcome. We conducted an ICD-10-based retrospective chart review on children hospitalized with pFP between January 1, 2006, and December 31, 2016. Furthermore, a telephone-based follow-up survey was performed. A total of 158 patients were identified, with a median age of 10.9 years (interquartile range 6.4-13.7). An infectious disease was associated with pFP in 82 patients (51.9%); 73 cases were classified as idiopathic pFP (46.2%). Three cases occurred postoperatively or due to a peripheral tumor. Among the infectious diseases, we identified 33 cases of neuroborreliosis and 12 viral infections of the central nervous system (CNS), caused by the varicella-zoster virus, human herpesvirus 6, herpes simplex virus, enterovirus, and Epstein-Barr virus. Other infections were mainly respiratory tract infections (RTIs; 37 cases). Children with an associated CNS infection had more often headache and nuchal rigidity, a higher cerebrospinal fluid cell count, and a longer length of hospital stay. Long-term follow-up revealed an associated lower risk of relapse in CNS infection-associated pFP. Among all groups, permanent sequelae were associated with female sex, a shorter length of hospitalization, and a lower white blood cell count at presentation. pFP is frequently caused by an CNS infection or is associated with concurrent RTIs, with a potential impact on the short- and long-term clinical course.