Bell's Palsy (Guidelines)

TAM (Treatments and Medicines) NHS Highland
NHS Highland

Audience

  • All NHS Highland
  • Primary and Secondary Care
  • Adults only

Bell’s Palsy is the commonest cause of facial paralysis. 1 person in 70 is affected during their lifetime, and can occur at any age, including children. It affects men and women equally. Exact aetiology is unclear but a viral (herpetic) cause is thought to be likely in many cases. Pregnancy and diabetes increase the risk of Bell’s Palsy.

History

The weakness is initially progressive, reaching its maximum within a few weeks or less. Most patients recover over three to six months.

Main symptoms:

The main symptom is facial weakness, with eyebrow sagging and difficulty closing the eye on the affected side. Patients may have many other symptoms including:

  • Facial asymmetry
  • Difficulty speaking
  • Dribbling or drooling
  • Food collecting between the cheeks and gums.

Some patients have:

  • Disturbed taste (the facial nerve carries signals for taste from the anterior two thirds of the tongue)
  • Dry eye
  • Excessive tears on the affected side (the facial nerve carries fibres to the tear glands)
  • Reduced ability to tolerate ordinary levels of noise (the facial nerve has a branch that supplies stapedius)
  • Ear pain.

To assess risk of Lyme disease:

  • Attached ticks in last 6 months
  • Rash in last 6 months that could be erythema migrans (a red or purple patch increasing in size over weeks, may have a ring appearance but often not)
  • Exposure to tick habitat in last 6 months. In Highland ticks are common in woodland, heathland and rough grassland and also present in gardens and city parks.
  • Recent or current headache, fatigue, flu like symptoms, radiculitis (radiculitis presents as nerve type pain)

Examination

  • Lower Motor Neurone facial weakness, ie, affecting the entire face (as opposed to Upper Motor Neurone weakness in stroke, which spares the forehead).
  • Assess for presence of vesicles on face, looking specifically in the external auditory meatus, roof of mouth and tip of nose, which suggest Ramsay Hunt Syndrome.
  • Examine tympanic membrane and parotid gland.
  • Examine skin for rash suggestive erythema migrans
  • Examine ear lobe for lymphocytoma (purplish swelling).

Grading severity:

Correlates with prognosis and helps to assess recovery.

House-Brackmann grading of weakness:

1. Normal

Good prognosis

2. Slight weakness

3. Obvious but not disfiguring asymmetry (eye closure)

  

4. Obvious and disfiguring asymmetry (no eye closure)

  

5. Barely perceptible movement

Poor prognosis

6. Total paralysis
Patients should have NO other associated neurological, infective or mass findings elsewhere on examination; if present need to consider other potential causes.

Investigation

There are NO investigations that can confirm Bell's Palsy.
  • If the facial nerve weakness is upper motor in origin then you should look for the presence of an intracranial lesion (such as stroke or tumour) by brain imaging. The involvement of other cranial nerve lesions suggests either a structural lesion (such as a cerebellopontine angle tumour) or a more diffuse inflammatory cause.
  • If the patient has been exposed to tick habitat in the last 6 months OR has any features of Lyme disease then send blood (serum) for Lyme disease testing. This will include most patients in Highland.
    A negative initial test does NOT exclude Lyme disease, so if the result is negative, repeat at 2 weeks and 6 weeks (for patients who present initially to ED, the follow up bloods should be done in primary care). See: Lyme disease (Guidelines) 
  • If vesicles are seen: take viral swab of the vesicle fluid and send for HSV/VZV/enterovirus PCR.

Other possible causes

Other possible causes of a unilateral facial nerve palsy:

  • Lyme disease. This is much more common in Highland than elsewhere in the UK.
    See: Lyme disease (Guidelines)
  • Diabetes.
  • Hypertension / As with diabetes this is probably due to microvascular compromise of the nerve.
  • Bacterial infection of the middle ear / cholesteatoma. This is usually obvious.
  • Parotid tumour: examine the patient for a parotid mass.
  • Facial trauma: either damage to the temporal bone or stylomastoid foramen may damage the facial nerve.

Rare causes include:

  • HIV infection: this facial nerve palsy is 100 times more common in HIV positive patients than in
    immunocompetent patients.
  • Syphilis.
  • Sarcoidosis: this may also cause bilateral facial nerve palsies.

Bilateral Bell's palsy is rare.

Immediately refer patients with bilateral lower motor neuron facial nerve palsy to a neurologist because their symptoms are more likely to have another cause, such as:

  • Guillain-Barré syndrome (look for absent reflexes in the limbs).
  • Myasthenia gravis (look for ocular signs such as fatigable ptosis or extraocular palsies).
  • Neurosarcoidosis
  • Lyme disease

Management

  • Most patients will recover without any treatment within 3 to 6 months.
  • Most patients do not require specialty referral, but should follow up with their GP.
  • Patients with Lyme disease require antibiotics.
    If tick habitat exposed or clinical features of Lyme disease, discuss with ID consultant. See: Lyme disease (Guidelines) 

Eye Care

  • Artificial tears, lubricant, eye patch or tape at night.
  • Unable to close eye = unable to protect cornea → refer to Ophthalmology.

Prednisolone

Dose: Prednisolone 60mg daily for 5 days, followed by daily reduction of 10mg up to day 10

Day Dosage
Days 1 to 5 60mg
Day 6 50mg
Day 7 40mg
Day 8 30mg
Day 9 20mg
Day 10 10mg
  • If given within 72 hours: increases chance of full recovery (81.6% Vs 94.4% at 9 months).
  • Seek advice prior to giving to patients who are pregnant or have diabetes, glaucoma or peptic ulceration.

Antivirals

  • NO evidence to support routine use
  • Only of use in Ramsay Hunt Syndrome (search for vesicles).

Prognosis

  • Most patients recover within 9 months.
  • Prognosis is related to the initial severity of presentation.
  • Prognosis is not as good with increased age, pregnancy and diabetes.

Editorial Information

Last reviewed: 27/02/2025

Next review date: 29/02/2028

Author(s): Emergency Department.

Version: 3

Co-Author(s): Infectious Diseases.

Approved By: TAMSG of the ADTC

Reviewer name(s): M Rennie, Service Clinical Director, Accident and Emergency , A Cain, Consultant, ENT, A Cochrane, Consultant in Infectious Diseases & Microbiology.

Document Id: TAM651