Can Lyme disease cause Bell's palsy?

Lyme Disease Can Cause Bell's Palsy

Yes, Lyme disease can definitely cause Bell's palsy, particularly in endemic areas where it may account for up to 25% of facial paralysis cases. 1

Relationship Between Lyme Disease and Bell's Palsy

Lyme disease is one of the established causes of facial paralysis that can present similarly to idiopathic Bell's palsy. Understanding this relationship is critical for proper diagnosis and treatment:

• In Lyme-endemic areas, Borrelia burgdorferi infection can cause up to 25% of facial paralysis cases 1
• Facial nerve palsy is the most common neurologic manifestation of the second stage of Lyme neuroborreliosis 2
• Lyme-associated facial palsy differs from idiopathic Bell's palsy in important ways

Clinical Characteristics of Lyme-Associated Facial Palsy

Several features can help distinguish Lyme-associated facial palsy from idiopathic Bell's palsy:

• Seasonal pattern: Lyme-associated facial palsy shows a strong seasonal pattern with peak incidence in summer months (particularly August), while Bell's palsy occurs more evenly throughout the year 3, 4
• Associated symptoms: Patients with Lyme-associated facial palsy often have:
  • Additional neurological symptoms beyond the facial weakness 3
  • History of erythema migrans rash (in approximately 66% of cases) 4
  • Systemic symptoms like fever, headache, or arthralgia 5
  • Painful radiculopathy in some cases 4
• Bilateral involvement: Bilateral facial palsy is more common in Lyme disease and should raise suspicion, especially when involvement is sequential 4
• CSF findings: Patients with Lyme neuroborreliosis typically have elevated mononuclear cells and albumin in cerebrospinal fluid 3
• Age distribution: Lyme-associated facial palsy tends to affect younger patients (mean age 41.7 years) compared to idiopathic Bell's palsy (mean age 59.6 years) 6

Diagnostic Approach

When evaluating facial paralysis in Lyme-endemic regions:

• Targeted testing is recommended rather than routine laboratory testing for all Bell's palsy cases 1
• Lyme disease serology should be obtained for patients:
  • In or recently traveled to endemic areas
  • With history suggestive of tick exposure
  • With atypical features for Bell's palsy (bilateral involvement, additional neurological symptoms)
  • Presenting during peak Lyme season (summer months) 1, 6
• Two-step testing process is typically used:
  1. Screening with ELISA or IFA
  2. Confirmation with Western blot if screening is positive or borderline 1

Treatment Implications

The distinction between Lyme-associated facial palsy and idiopathic Bell's palsy is crucial because treatment differs:

• Idiopathic Bell's palsy: Treated with corticosteroids
• Lyme-associated facial palsy: Requires antibiotic therapy (typically doxycycline) 3, 2

Importantly, retrospective data suggests that adding corticosteroids to antibiotic therapy for Lyme-associated facial palsy does not appear to affect recovery speed or overall outcome 4. However, misdiagnosis of Lyme-associated facial palsy as Bell's palsy could lead to inappropriate treatment with steroids alone, without the necessary antibiotics.

Geographic Considerations

The risk of Lyme-associated facial palsy varies geographically:

• In the United States, it's more common in northeastern and upper midwestern states
• In Canada, endemic regions include southern Ontario, Nova Scotia, southern Manitoba, New Brunswick, and southern Quebec 2
• In England, there's been a 42% annual increase in Lyme disease diagnoses from 2011-2015, with higher incidence in rural areas 6

Conclusion

When evaluating a patient with facial paralysis, particularly in Lyme-endemic regions, clinicians should maintain a high index of suspicion for Lyme disease. The presence of additional neurological symptoms, bilateral involvement, summer presentation, or history of rash should prompt Lyme disease testing to ensure appropriate antibiotic treatment.