What is the recommended oral corticosteroid regimen for acute Bell's palsy and when should antiviral therapy be added?

Management of Bell's Palsy with Oral Steroids

Prescribe prednisolone 50 mg daily for 10 days OR prednisone 60 mg daily for 5 days followed by a 5-day taper, initiated within 72 hours of symptom onset for all patients aged 16 years and older. 1, 2

Critical Timing Window

• Treatment must begin within 72 hours of symptom onset—this is a hard deadline, as no high-quality evidence supports benefit beyond this window. 1, 2, 3
• Patients presenting at day 5 or later should NOT receive steroids; focus instead on eye protection and monitoring for recovery. 3
• The 72-hour window exists because early corticosteroid treatment reduces facial nerve inflammation before permanent damage occurs. 3

Specific Steroid Regimens

Two evidence-based options exist:

• Prednisolone 50 mg once daily for 10 days (no taper required), OR 1, 2
• Prednisone 60 mg once daily for 5 days, then taper over 5 days 1, 2

Dosing details:

• Administer as a single morning dose to align with natural cortisol rhythm and minimize sleep disturbance. 2
• Maximum daily dose should not exceed 60 mg. 2
• For significantly underweight or overweight patients, consider weight-based dosing at 1 mg/kg/day (maximum 60 mg). 2

Evidence Supporting Steroid Use

The benefit is substantial and well-established:

• 83% complete recovery at 3 months with prednisolone versus 63.6% with placebo (absolute benefit +19.4%, NNT = 6). 2, 4
• 94.4% complete recovery at 9 months with prednisolone versus 81.6% with placebo (absolute benefit +12.8%, NNT = 8). 2, 4
• This represents a strong recommendation based on high-quality randomized controlled trials. 1

Role of Antiviral Therapy

Antivirals should NEVER be prescribed as monotherapy—this is ineffective and delays appropriate treatment. 1, 2, 5

Optional combination therapy:

• May offer valacyclovir 1000 mg three times daily for 7 days OR acyclovir 400 mg five times daily for 10 days in addition to steroids within 72 hours. 1, 2, 5
• The added benefit is minimal: combination therapy achieves 96.5% recovery versus 89.7% with steroids alone in severe cases (absolute benefit +6.8%). 6
• This is classified as an "option" rather than a recommendation due to the small incremental benefit. 1, 2
• Some evidence suggests combination therapy may reduce synkinesis rates. 5

Special Population: Diabetes

Diabetes is NOT a contraindication to corticosteroid therapy—the therapeutic benefit outweighs the risk of temporary hyperglycemia. 2

Glucose management strategy:

• Monitor capillary blood glucose every 2-4 hours during the first few days of steroid therapy. 2
• Proactively increase basal insulin and add or increase prandial insulin to counter steroid-induced hyperglycemia. 2
• For patients on oral agents, add NPH insulin concurrent with the morning steroid dose (NPH peaks 4-6 hours later, matching the hyperglycemic effect). 2
• Do NOT withhold steroids due to diabetes concerns. 2

Special Population: Pregnancy

• Pregnant women should receive oral corticosteroids within 72 hours with careful assessment of benefits and risks. 2
• Pregnant women have excellent prognosis with up to 90% complete recovery rates. 5
• Eye protection measures are essential and safe in pregnancy. 2

Special Population: Children

• Children have better prognosis than adults with higher spontaneous recovery rates (up to 90%). 2, 5
• Evidence for steroid benefit in children is less conclusive than in adults. 2
• Consider oral steroids on an individualized basis with substantial caregiver participation in shared decision-making. 2
• If treating, use prednisolone 1 mg/kg/day (maximum 50-60 mg) for 5 days followed by a 5-day taper. 2

Essential Eye Protection (Mandatory for All Patients)

Implement immediately for any patient with impaired eye closure:

• Lubricating ophthalmic drops every 1-2 hours while awake. 1, 2
• Ophthalmic ointment at bedtime for sustained moisture retention. 1, 2
• Eye taping or patching at night with careful instruction on proper technique to avoid corneal abrasion. 1, 2
• Sunglasses outdoors for protection against wind and foreign particles. 1, 2
• For severe impairment with complete inability to close the eye, refer urgently to ophthalmology. 2

Diagnostic Testing NOT Recommended

• Do NOT obtain routine laboratory testing—it delays treatment without improving outcomes. 1, 2
• Do NOT perform routine diagnostic imaging—reserve MRI with and without contrast for atypical presentations only. 1, 2
• Do NOT perform electrodiagnostic testing in patients with incomplete facial paralysis—it provides no actionable information. 1, 2

Mandatory Follow-Up and Referral Triggers

Refer to a facial nerve specialist if:

• Incomplete facial recovery at 3 months after symptom onset. 1, 2
• New or worsening neurologic findings at any point. 1, 2
• Development of ocular symptoms at any point. 1, 2

Red Flags Suggesting Alternative Diagnosis

These features require immediate imaging and specialist referral:

• Recurrent paralysis on the same side. 2
• Isolated branch paralysis (not affecting entire hemiface). 2
• Other cranial nerve involvement. 2
• Bilateral facial weakness. 2
• Progressive weakness beyond 3 weeks. 2

Common Pitfalls to Avoid

• Do NOT start steroids after 72 hours—this exposes patients to medication risks without proven benefit. 3
• Do NOT prescribe antivirals alone—this is ineffective and delays appropriate corticosteroid treatment. 1, 2, 5
• Do NOT use standard methylprednisolone dose packs—these provide only 105 mg prednisone equivalent versus the required 540 mg over 14 days, representing significant underdosing. 2
• Do NOT restart or extend corticosteroids beyond the initial 10-day course—evidence supports only the initial treatment window. 7
• Do NOT neglect eye protection—inadequate protection can lead to permanent corneal damage. 2, 7
• Do NOT fail to refer at 3 months if recovery is incomplete—this delays access to reconstructive options. 2

Therapies NOT Recommended

• Physical therapy: No proven benefit over spontaneous recovery, though may be considered for severe paralysis with developing synkinesis. 2, 5
• Acupuncture: No recommendation can be made due to poor-quality trials. 2
• Surgical decompression: Not recommended except in rare cases at specialized centers. 1, 2

Expected Natural History

• Approximately 70% of patients with complete paralysis recover completely within 6 months even without treatment. 2, 3
• Patients with incomplete paralysis have recovery rates up to 94%. 2, 3
• Most patients begin showing signs of recovery within 2-3 weeks of symptom onset. 3, 7
• With appropriate steroid treatment, 94.4% achieve complete recovery by 9 months. 2, 4