Peripheral facial nerve palsy in children in a Borrelia high-endemic area, a retrospective follow-up study.

Aim: To identify the incidence, aetiology and prognosis of acute peripheral facial nerve palsy (FNP) in children in the Borrelia high-endemic region of Stockholm.

Methods: The present study identified children from 0 to 18 years of age who visited a paediatric emergency department for acute peripheral FNP during a 1-year period from 2014 to 2015. Data were collected retrospectively. The Sunnybrook and House-Brackmann facial grading systems were used to measure clinical outcome.

Results: A total of 77 children were identified with FNP, an estimated incidence of 30 per 100 000 children/year. Forty-five children (58%) were diagnosed with neuroborreliosis, 28 (36%) with idiopathic FNP and four (6%) with other rarer causes. Neuroborreliosis was common from June to November and mainly seen in children below 10 years of age. Six patients (8%) had remaining symptoms at least 3 months after onset; three had idiopathic facial palsy (IFP) and were all older than 10 years, one had neuroborreliosis and two had other causes.

Conclusion: Neuroborreliosis and IFP were the major causes of FNP during the study period. Neuroborreliosis-associated facial palsy had a seasonal variation and dominated in younger ages.