BACKGROUND AND OBJECTIVE: Corticosteroids are used to treat the early stages of idiopathic facial paralysis (Bell's palsy) in children, but their effectiveness is uncertain. We set out to determine if prednisolone improves the proportion of children with Bell's palsy with complete recovery at one month. METHODS: We conducted a double-blind, placebo-controlled, randomised trial of prednisolone in children presenting to emergency departments with Bell's palsy. Patients aged 6 months to less than 18 years, recruited within 72 hours after symptom onset, were randomly assigned to receive 10 days of treatment with oral prednisolone (approximately 1 mg/kg) or placebo. The primary outcome was complete recovery of facial function at 1 month rated on the House-Brackmann scale. Secondary outcomes included facial function, adverse events and pain up to 6 months. Target recruitment was n=540 (270 per group). RESULTS: Between 13 October 2015 to 23 August 2020, 187 children were randomised (94 to prednisolone and 93 to placebo) and included in the intention-to-treat analysis. At 1 month, the proportions of patients who had recovered facial function were 49% (n=43/87) in the prednisolone group compared with 57% (n=50/87) in the placebo group (risk difference -8.1%, 95% CI -22.8 to 6.7; adjusted odds ratio [aOR] 0.7, 95% CI 0.4 to 1.3). At 3 months these proportion were 90% (n=71/79) for the prednisolone group versus 85% (n=72/85) for the placebo group (risk difference 5.2%, 95%, CI -5.0 to 15.3; aOR 1.2, 95% CI 0.4 to 3.0) and at 6 months 99% (n=77/78) and 93% (n=76/82) respectively (risk difference 6.0%, 95% CI -0.1 to 12.2; aOR 3.0 95% CI 0.5 to 17.7) There were no serious adverse events and little evidence for group differences in secondary outcomes. DISCUSSION: In children with Bell's palsy the vast majority recover without treatment. The study, although underpowered, does not provide evidence that early treatment with prednisolone improves complete recovery. REGISTRATION: Registered with the Australian New Zealand Clinical Trials Registry ACTRN12615000563561, registered 1 June 2015, ://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368505&isReview=true CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for children with Bell's palsy, prednisolone does not significantly change recovery of complete facial function at one month. However, the study lacked the precision to exclude an important harm or benefit from prednisolone.
