Treatment of Bell's Palsy
Primary Treatment: Oral Corticosteroids Within 72 Hours
Start oral corticosteroids immediately for all patients 16 years and older who present within 72 hours of symptom onset—this is the only proven effective treatment that significantly improves complete recovery rates. 1, 2, 3
Recommended Corticosteroid Regimens
Choose one of the following evidence-based regimens:
- Prednisolone 50 mg daily for 10 days (preferred regimen) 2, 3
- Prednisone 60 mg daily for 5 days, followed by a 5-day taper 1, 2
The evidence supporting corticosteroids is robust: 83% of patients recover completely at 3 months with prednisolone versus 63.6% with placebo, and 94.4% recover at 9 months versus 81.6% with placebo. 3, 4 This represents a strong recommendation from the American Academy of Otolaryngology-Head and Neck Surgery based on high-quality randomized controlled trials. 2, 3
Critical Timing Window
Do not initiate corticosteroids if the patient presents after 72 hours of symptom onset—the evidence for benefit beyond this window is absent, and you expose patients to medication risks without proven benefit. 1 All clinical trials demonstrating steroid efficacy specifically enrolled patients within 72 hours, with no clear evidence supporting later administration. 1
Antiviral Therapy: Optional Combination, Never Alone
Never prescribe antiviral therapy as monotherapy—it is completely ineffective. 2, 3, 4 The American Academy of Otolaryngology-Head and Neck Surgery explicitly recommends against antiviral monotherapy. 2, 3
When to Consider Adding Antivirals
You may offer combination therapy (corticosteroids plus antivirals) within 72 hours as an option, though the added benefit is minimal. 2 Some evidence suggests slightly higher complete recovery rates with combination therapy (96.5%) compared to steroids alone (89.7%), but this represents a small incremental benefit. 2
If choosing combination therapy, use:
- Valacyclovir 1 g three times daily for 7 days, OR 5
- Acyclovir 400 mg five times daily for 10 days 5, 6
The 2007 landmark New England Journal of Medicine trial found no benefit of acyclovir alone or in combination with prednisolone, which is why corticosteroids remain the cornerstone of treatment. 4
Eye Protection: Mandatory for All Patients with Impaired Eye Closure
Implement aggressive eye protection immediately for any patient who cannot fully close their affected eye—corneal damage is a preventable complication that can cause permanent vision loss. 1, 2, 3
Structured Eye Protection Protocol
Daytime protection:
- Lubricating ophthalmic drops every 1-2 hours while awake 1, 3
- Sunglasses outdoors to protect against wind and foreign particles 1, 3
Nighttime protection (critical):
- Ophthalmic ointment at bedtime for sustained moisture retention 1, 3
- Eye taping or patching with careful instruction on proper technique to avoid corneal abrasion 1, 3
- Consider moisture chambers using polyethylene covers for severe cases 1, 3
Urgent ophthalmology referral if:
- Complete inability to close the eye 3
- Eye pain, vision changes, redness, or discharge develops 1
- Signs of corneal exposure or damage 3
The Bell's phenomenon (upward rotation of the globe during attempted eye closure) provides some natural protection, but is insufficient alone in patients with lagophthalmos. 3
Special Populations
Children
Children have excellent prognosis with spontaneous recovery rates up to 94%, significantly higher than adults. 2, 3, 5 The evidence for corticosteroid benefit in children is inconclusive, as most trials excluded pediatric patients. 1, 3 Consider oral corticosteroids (prednisolone 1 mg/kg/day, maximum 50-60 mg) for severe or complete paralysis cases with substantial caregiver involvement in shared decision-making. 3
Pregnant Women
Treat pregnant women with oral corticosteroids within 72 hours using individualized assessment of benefits and risks. 1, 3 Eye protection measures are essential and safe in pregnancy. 3 The favorable safety profile of short-term corticosteroids generally supports treatment, but discuss risks and benefits explicitly. 3
Follow-Up and Referral Triggers
Mandatory Reassessment or Specialist Referral
Refer to a facial nerve specialist or ophthalmologist if:
- Incomplete facial recovery persists 3 months after symptom onset 1, 2, 3
- New or worsening neurologic findings develop at any point 1, 2, 3
- Ocular symptoms develop at any point 1, 2, 3
Most patients begin showing signs of recovery within 2-3 weeks, with complete recovery typically occurring within 3-4 months. 3 Approximately 70% of patients with complete paralysis recover fully within 6 months, while those with incomplete paralysis have recovery rates up to 94%. 1, 3
Diagnostic Testing
Do not order routine laboratory testing or imaging for typical Bell's palsy presentations. 2, 3 The diagnosis is clinical, based on acute unilateral facial weakness involving the forehead with onset less than 72 hours and no identifiable cause. 3
Consider MRI with and without contrast only for atypical features: second paralysis on same side, isolated branch paralysis, other cranial nerve involvement, or no recovery after 3 months. 3
Electrodiagnostic testing (ENoG and EMG) may be offered to patients with complete facial paralysis, performed 3-14 days post-onset for reliable prognostic information. 3 Testing showing greater than 10% nerve response amplitude indicates excellent prognosis. 3
Common Pitfalls to Avoid
- Delaying treatment beyond 72 hours reduces effectiveness and exposes patients to medication risks without proven benefit 1, 2
- Using antiviral therapy alone is completely ineffective and delays appropriate corticosteroid treatment 2, 3
- Failing to provide adequate eye protection can lead to permanent corneal damage in patients with impaired eye closure 1, 2
- Not referring patients with incomplete recovery at 3 months delays access to reconstructive options and psychological support 3
- Failing to rule out other causes of facial weakness before diagnosing Bell's palsy (trauma, infection, tumor, stroke) 2, 3