What is the immediate workup for Bell's (Bell's palsy)?

Immediate Workup of Bell's Palsy

The immediate workup for Bell's palsy should focus on history and physical examination to exclude other causes of facial weakness, with no routine laboratory testing or imaging recommended unless specific alternative diagnoses are suspected. 1

Diagnostic Approach

History and Physical Examination (Essential Components)

• Confirm acute onset (<72 hours) of unilateral facial weakness/paralysis
• Assess for involvement of all facial nerve branches, including forehead
• Rule out identifiable causes through targeted assessment:
  • Check for vesicular lesions in ear canal (herpes zoster oticus)
  • Evaluate for other cranial nerve deficits (suggests central cause)
  • Assess for parotid masses or skin lesions
  • Document eye closure ability
  • Note any history of trauma, infection, or systemic disease

What NOT to Include in Initial Workup

• Routine laboratory testing is not recommended for new-onset Bell's palsy 1, 2
• Routine diagnostic imaging is not recommended for typical presentations 1, 2
• Electrodiagnostic testing is not recommended for patients with incomplete facial paralysis 1

Selective Testing (Only When Indicated)

• Laboratory testing only when specific conditions are suspected:
  • Lyme disease serology (in endemic areas or with suggestive history)
  • Blood glucose/HbA1c (if diabetes suspected)
• Imaging only when atypical features present:
  • Gradual onset (>72 hours)
  • Lack of improvement after 3 months
  • Recurrent episodes
  • Other neurologic abnormalities
  • Involvement of other cranial nerves

Immediate Management After Diagnosis

1. Oral corticosteroids should be prescribed within 72 hours of symptom onset for patients 16 years and older 1, 2

   • Typically prednisone 60-80 mg daily for 7 days with taper

2. Eye protection measures must be implemented for patients with impaired eye closure 1, 2

   • Artificial tears during the day
   • Lubricating ointment at night
   • Eye patch or taping for complete inability to close eye

3. Optional antiviral therapy may be considered in addition to steroids (not as monotherapy) 1, 2

   • Valacyclovir or acyclovir within 72 hours of onset

Follow-up Planning

• Arrange reassessment or referral to facial nerve specialist if:
  • New or worsening neurologic findings develop
  • Ocular symptoms develop
  • Incomplete facial recovery after 3 months 1

Common Pitfalls to Avoid

1. Misdiagnosis: Bell's palsy is a diagnosis of exclusion. Central causes (stroke) must be ruled out by confirming forehead involvement and absence of other neurologic deficits.

2. Delayed treatment: Corticosteroid therapy is most effective when started within 72 hours of symptom onset; efficacy diminishes with delay 2.

3. Inadequate eye protection: Corneal damage from exposure is the most common complication and is preventable with proper eye care 1, 2.

4. Using antivirals alone: Antiviral monotherapy is not recommended and should only be considered as an adjunct to steroids 1, 2.

5. Missing bilateral involvement: Bilateral Bell's palsy is rare and should prompt investigation for other conditions like Guillain-Barré syndrome or Lyme disease 1.