Bell's Palsy: Initial Treatment
Prescribe oral corticosteroids within 72 hours of symptom onset for all patients 16 years and older with acute Bell's palsy—this is the only proven treatment that significantly improves facial nerve recovery. 1
Recommended Corticosteroid Regimens
Choose one of the following evidence-based regimens, initiated within the critical 72-hour window:
Prednisolone 50 mg once daily for 10 days (no taper required), which achieves 83% complete recovery at 3 months versus 63.6% with placebo (absolute benefit 19.4%; NNT = 6) 1
Prednisone 60 mg once daily for 5 days, followed by a 5-day taper (reduce by 10 mg daily: 50→40→30→20→10 mg, then stop), which demonstrates 94.4% recovery at 9 months versus 81.6% with placebo 1
Both regimens are equally effective; the choice depends on patient preference and local formulary availability. 1
Eye Protection: Mandatory for All Patients with Incomplete Eye Closure
Implement the following measures immediately to prevent permanent corneal damage:
Lubricating ophthalmic drops every 1–2 hours while awake to maintain corneal hydration 1
Ophthalmic ointment at bedtime for sustained overnight moisture retention 1
Eye taping or patching at night with careful instruction on proper technique to avoid corneal abrasion 1
Sunglasses outdoors to protect against wind, debris, and foreign particles 1
Urgent ophthalmology referral for patients with severe lagophthalmos (complete inability to close the eye) or any signs of corneal exposure (pain, redness, vision changes) 1
Antiviral Therapy: Optional Adjunct Only
Never prescribe antiviral monotherapy—it is completely ineffective and delays appropriate corticosteroid treatment. 1
Combination therapy (antiviral + corticosteroid) may be offered within 72 hours for severe cases, though the added benefit is modest: 96.5% recovery versus 89.7% with steroids alone (absolute benefit 6.8%) 1
If combination therapy is chosen, use valacyclovir 1000 mg three times daily for 7 days or acyclovir 400 mg five times daily for 10 days 1
The American Academy of Otolaryngology-Head and Neck Surgery classifies combination therapy as an "option" rather than a recommendation due to the small incremental gain 1
Diagnostic Testing: What NOT to Do
Avoid routine laboratory testing and imaging in typical Bell's palsy presentations—these delay treatment beyond the critical 72-hour window without improving outcomes. 1
No blood tests (CBC, metabolic panel, Lyme serology) unless history suggests a specific alternative diagnosis 1
No routine CT or MRI for new-onset cases with classic features (acute onset <72 hours, isolated unilateral facial weakness including forehead, no other neurologic deficits) 1
No electrodiagnostic testing for patients with incomplete facial paralysis, as it provides no actionable information 1
Confirming the Diagnosis: Essential Clinical Features
Before initiating treatment, verify these diagnostic criteria:
Rapid onset within 72 hours of unilateral facial weakness involving the entire ipsilateral face, including the forehead 1
No identifiable cause after thorough history and physical examination excluding trauma, infection, tumor, or stroke 1
Complete cranial nerve examination showing no involvement of other cranial nerves (CN V, VI, VIII, IX, X, XI, XII)—any additional deficit excludes Bell's palsy and mandates imaging 1
Forehead involvement (inability to wrinkle forehead or raise eyebrow) distinguishes peripheral Bell's palsy from central stroke, which spares the forehead 1
Red Flags Requiring Imaging and Specialist Referral
Order MRI (with and without contrast) immediately if any of the following are present:
Forehead sparing (suggests central stroke rather than peripheral palsy) 1
Other cranial nerve involvement (indicates brainstem or skull base pathology) 1
Bilateral facial weakness (extremely rare in Bell's palsy; suggests Lyme disease, Guillain-Barré syndrome, or sarcoidosis) 1
Recurrent paralysis on the same side (suggests tumor or structural lesion) 1
Isolated branch paralysis (not consistent with Bell's palsy) 1
Progressive weakness beyond 3 weeks (raises concern for neoplasm or infection) 1
Additional neurologic symptoms (dizziness, dysphagia, diplopia, limb weakness, altered mental status) 2
Special Populations
Pregnant Women
Treat with oral corticosteroids within 72 hours after individualized risk-benefit assessment—the therapeutic benefit outweighs the risk of temporary hyperglycemia 1
Eye protection measures are essential and safe in pregnancy 1
Children
Children have better prognosis than adults (up to 94% spontaneous recovery), but corticosteroid benefit in pediatrics remains inconclusive 1
Consider oral corticosteroids on an individualized basis with substantial caregiver participation in shared decision-making, using prednisolone 1 mg/kg/day (maximum 50–60 mg) for 5 days followed by a 5-day taper 1
Patients with Diabetes
Diabetes is not a contraindication to corticosteroid therapy—the therapeutic benefit outweighs the risk of temporary hyperglycemia 1
Monitor capillary blood glucose every 2–4 hours during the first few days and proactively adjust diabetes medications (increase basal insulin, add or increase prandial insulin) 1
Mandatory Follow-Up and Referral Triggers
Reassess or refer to a facial nerve specialist at 3 months if facial recovery is incomplete 1
Immediate referral for new or worsening neurologic findings at any point 1
Immediate ophthalmology referral for development of ocular symptoms (pain, redness, vision changes, foreign body sensation) at any point 1
Interventions NOT Recommended
Do not prescribe or recommend the following—they lack proven benefit and may delay effective treatment:
Physical therapy (no proven benefit over spontaneous recovery) 1
Acupuncture (poor quality evidence with indeterminate benefit-harm ratio) 1
Surgical decompression (rarely indicated except in highly selected cases at specialized centers) 1
Common Pitfalls to Avoid
Delaying corticosteroid therapy beyond 72 hours eliminates the treatment benefit—no evidence supports starting steroids after this window 1
Using a standard methylprednisolone dose pack provides only 105 mg prednisone-equivalent total (versus the required 540 mg over 10–14 days), representing significant underdosing 1
Prescribing antiviral monotherapy is completely ineffective and delays appropriate steroid treatment 1
Ordering unnecessary labs or imaging increases cost, delays treatment, and offers no clinical benefit in typical presentations 1
Failing to test forehead function can lead to misdiagnosis—forehead involvement is critical to distinguish Bell's palsy from central stroke 1
Missing other cranial nerve involvement delays diagnosis of serious central pathology requiring different management 1
Inadequate eye protection can lead to permanent corneal damage, particularly in patients with severe lagophthalmos 1