Bell’s palsy
NICE CKS Bell’s palsy. Last revised Feb 2023.
Background Information
Definition
Acute unilateral facial nerve palsy of unknown cause.
Herpes simplex virus, herpes zoster virus, and autoimmunity may contribute to the development of Bell's palsy, but the exact pathogenesis is controversial and the significance of these factors remains unclear
Clinical Features
Symptoms suggestive of Bell's palsy:
- Rapid onset (<72 hours)
- Unilateral facial weakness / paralysis
- Post-auricular and ear pain (~50%)
- Change in taste (~35%)
- Difficulty chewing and dry mouth (~20%)
- Dry eyes (30%), eye pain, excessive tearing
- Poor / incomplete eye closure
- Hyperacusis (<5%)
Guidelines
Investigation and Diagnosis
Clinical diagnosis, when no other medical condition is thought to be causing the facial weakness / paralysis.
Management
Referral Criteria
Referral to specialist is recommended if:
- Facial nerve palsy may be caused by upper motor neuron cause or cancer or trauma
- No improvement after 3 weeks of treatment
- Incomplete recovery after 3 months of onset
- Worsening / new neurological findings
General Advice / Conservative Management
Advise that Bell's palsy improves at different rates and maximum recovery can take several months.
Advice on eye care:
- Keep the affected eye lubricated (eye drops during the day and eye ointment at night)
- Tape the eye closed at night if unable to close the eye
- Eye patches are contraindicated as the eye may open under the patch, leading to corneal abrasion
- Wear sunglasses when outdoors
- Avoid eye irritation activity (e.g. swimming and dusty environments)
Pharmacological Management
Consider oral prednisolone if present <72 hours of onset
- 50 mg daily for 10 days OR
- 60 mg daily for 5 days followed by a daily reduction in dose of 10 mg (for a total treatment time of 10 days)
Antiviral treatments alone are NOT recommended. Antiviral treatment in combination with a corticosteroid may be of small benefit, but seek specialist advice if this is being considered.