Bell's Palsy Quick Guide

Key Features

  • Acute unilateral LMN facial paralysis
  • Affects upper and lower face
  • Rapid onset (<72 hours)
  • Postauricular pain common

Red Flags

  • Gradual/progressive onset
  • Bilateral symptoms
  • Other cranial nerve involvement
  • UMN pattern (spares forehead)

Treatment

Steroids: Prednisolone 50mg x10d or 60mg x5d then taper

Start within 72h of onset

Antivirals not recommended alone

Eye Care

  • Artificial tears (daytime)
  • Ointment at night
  • Taping if incomplete closure
  • Ophthalmology referral if corneal damage

Prognosis

  • Most recover fully in 3-4 months
  • Complete paralysis has worse prognosis
  • Age >60 and diabetes reduce recovery

Bell's Palsy

Diagnosis and Management Guidelines

Bell's palsy is an acute, unilateral, idiopathic, isolated, lower motor neuron facial nerve paralysis. The cause of Bell's palsy is unknown. Herpes simplex virus, varicella 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.

Key Feature: Lower motor neuron lesion affecting both upper and lower facial muscles (unlike stroke which typically spares forehead movement).

Epidemiology

Incidence

  • 20-30 cases per 100,000 annually
  • Equal gender distribution
  • Recurrence rate: 7-15%

Risk Factors

  • Age 15-45 years (peak incidence)
  • Diabetes (4-5x increased risk)
  • Pregnancy (3x higher risk, especially 3rd trimester)
  • Recent upper respiratory infection
  • Hypertension

Diagnosis

Typical Presentation

  • Rapid onset (<72 hours) of unilateral facial weakness
  • Affects both upper and lower face (LMN pattern)
  • Postauricular pain (50% of cases)
  • Taste changes (35%) - anterior 2/3 of tongue
  • Hyperacusis (stapedius muscle paralysis)
  • Decreased tearing (greater petrosal nerve)

Red Flags

  • Gradual/progressive onset (>72 hours)
  • Bilateral symptoms (consider Guillain-BarrĂ©)
  • Other cranial nerve involvement
  • Vesicular rash (Ramsay-Hunt syndrome)
  • Spares forehead (suggests UMN lesion - stroke)
  • History of Lyme disease exposure

Diagnostic Note: Bell's palsy is a diagnosis of exclusion. No routine lab tests or imaging required for typical presentations. Consider further workup if red flags present.

House-Brackmann Grading System

  • Grade I: Normal function
  • Grade II: Mild dysfunction
  • Grade III: Moderate dysfunction
  • Grade IV: Moderately severe dysfunction
  • Grade V: Severe dysfunction
  • Grade VI: Total paralysis

Differential Diagnosis

Neurological

  • Stroke (UMN pattern spares forehead)
  • Brain tumor (acoustic neuroma, meningioma)
  • Multiple sclerosis
  • Guillain-BarrĂ© syndrome (bilateral)

Infectious

  • Lyme disease (erythema migrans rash)
  • Ramsay-Hunt syndrome (VZV + ear vesicles)
  • HIV/syphilis
  • Otitis media/mastoiditis

Other

  • Trauma/surgery (temporal bone fracture)
  • Parotid tumors
  • Sarcoidosis (Heerfordt syndrome)
  • Diabetes mellitus

Management

Eye Care

  • Artificial tears (preservative-free, every 2h while awake)
  • Ointment at night (lacrilube or equivalent)
  • Taping eye closed at night if incomplete closure
  • Moisture chamber glasses if severe lagophthalmos
  • Avoid irritants (dust, wind, swimming)
  • Ophthalmology referral if corneal damage

Medications

  • Prednisolone: 50mg daily x10d or 60mg x5d then taper over 5 days
  • Start within 72h of onset (earlier better)
  • Antivirals (acyclovir/valacyclovir) not recommended alone
  • Combination therapy (steroids + antivirals) may be considered in severe cases
  • Analgesics for pain management

Prognosis & Follow-up

  • Most (70%) recover fully within 3-4 months
  • Reassure patients about natural history
  • Follow-up at 1 month to assess recovery
  • Refer to ENT if no improvement by 3-4 months
  • Consider physical therapy for synkinesis

Complications

Ocular

  • Corneal abrasion/ulceration
  • Exposure keratitis
  • Vision loss (rare)

Neurological

  • Synkinesis (abnormal facial movements)
  • Hyperacusis (sound sensitivity)
  • Chronic facial weakness (10-15% of cases)
  • Crocodile tears (gustatory lacrimation)

Other

  • Dry mouth (chorda tympani involvement)
  • Psychological impact (depression, anxiety)
  • Facial pain (chronic neuralgia)
  • Speech and eating difficulties