Clinical characteristics of children with Borrelia-related peripheral facial palsy and utility of cerebrospinal fluid testing

Aim: To describe the aetiology and clinical characteristics of acute peripheral facial palsy (PFP) in children and investigate the utility of the European Federation of Neurological Societies (EFNS) criteria for diagnosing Borrelia-related PFP (BPFP) based on cerebrospinal fluid (CSF) testing and the Centers for Disease Control and Prevention (CDC) criteria based on serology. Methods: We retrospectively identified children aged <18 years diagnosed with acute PFP between 2014 and 2020. We used the EFNS criteria as the gold standard and the CDC criteria for diagnosing BPFP. Results: Out of 257 children with PFP, 93 (36%) fulfilled the EFNS or CDC criteria for BPFP. We found a discrepancy between the EFNS criteria with CSF testing and the CDC without CSF testing in 27 (14%) of the 190 children with available data. Of the 37 children with PFP and >= 2 symptoms of fever, fatigue, nausea/vomiting or meningeal symptoms, 31 (84%) fulfilled the EFNS criteria for BPFP. Conclusion: Borrelia is a common cause of PFF in children, and its prevalence is higher in children with systemic symptoms. Also, CSF testing did not have decisive management implications in most cases. Therefore, clinical evaluation and Borrelia serology could be the initial steps in the diagnosis of PFP in children.