■ OBJECTIVES: Oral corticosteroids and antiviral agents are widely used in idiopathic facial paralysis (Bell’s palsy), but their effectiveness is uncertain. We aimed to determine whether early administration of prednisolone and/or acyclovir improved the outcome in Bell’s palsy.

■ METHODS:We conducted a 2 x 2 factorial randomized, doubleblind trial throughout Scotland in patients within 72 hours of onset of Bell’s palsy. Patients were randomized to treatment for ten days with: (1) prednisolone (50mg per day) and placebo, (2) acyclovir (2000 mg per day) and placebo, (3) prednisolone and acyclovir, and (4) placebo and placebo. The primary outcome was recovery of facial function assessed by the House Brackmann scale.

■ RESULTS: 551 patients were recruited and randomized to treatment group. 496 (90%) patients completed the study. Three month assessments were made on all patients: the proportions assessed at House Brackmann grade I (indicating complete recovery) were: 83.0% for prednisolone compared with 63.6% for no prednisolone, p<0.001; 71.2% for acyclovir compared with 75.7% for no acyclovir, p=0.30. At nine month assessments, the proportions of patients assessed at House Brackmann grade I were: 94.4% for prednisolone compared with 81.6% for no prednisolone, p<0.001; and 85.4% for acyclovir compared with 90.8% for no acyclovir, p=0.07. Prednisolone was more effective than no prednisolone, both at three months and at nine months. The NNT was 6 (95% CI 4 to 9) at three months and 8 (95% CI 6 to 14) at nine months.