Lyme Disease vs Bell’s Palsy: When Facial Paralysis Is Misdiagnosed
Facial paralysis may not be idiopathic
Lyme disease can mimic Bell’s palsy
Delayed diagnosis can worsen outcomes
Lyme disease Bell’s palsy misdiagnosis can lead to serious neurologic complications when infection is not recognized early.
This case highlights how delayed diagnosis of Lyme neuroborreliosis left a young woman bedridden for months before appropriate treatment was initiated.
These diagnostic challenges are also seen in Lyme disease misdiagnosis, where atypical presentations lead to delayed care.
Initial Presentation: Facial Palsy Misdiagnosed
The patient initially developed facial weakness during pregnancy, including:
- Deviation of the mouth
- Decreased taste sensation
- Difficulty closing the eyes
- Difficulty whistling
She was diagnosed with Bell’s palsy, and Lyme disease was not considered.
At the time, there was also a history of recent fever—an important clinical clue.
Progressive Neurologic Deterioration
Over time, the patient developed worsening neurologic symptoms:
- Severe lancinating pain radiating from the neck and back
- Weakness in all four limbs
- Progression to quadriparesis
- Bedridden status
Standard Bell’s palsy treatment with corticosteroids did not improve her condition.
Failure to respond to expected therapy should prompt reconsideration of the diagnosis.
Diagnosis: Lyme Neuroborreliosis
Further testing revealed Lyme disease through ELISA and PCR testing.
She was treated with intravenous ceftriaxone and oral azithromycin.
Her recovery was significant:
- Walking independently by 3 months
- No neurologic deficits at 6 months
This dramatic improvement confirmed Lyme neuroborreliosis rather than idiopathic Bell’s palsy.
For more on neurologic involvement, see neurologic Lyme disease.
Why Lyme Disease Is Missed
Several factors contributed to delayed diagnosis:
- Geographic assumptions about Lyme disease prevalence
- Absence of classic erythema migrans rash
- Initial diagnosis of Bell’s palsy
- Failure to recognize systemic symptoms
These issues are common in atypical cases, especially when symptoms overlap with those in the Lyme disease symptoms guide.
Warning Signs That It May Not Be Bell’s Palsy
Clinicians should reconsider the diagnosis when facial paralysis is accompanied by:
- Fever or recent illness
- Progressive or bilateral symptoms
- Neurologic deficits beyond facial weakness
- Poor response to corticosteroids
- Radicular pain or limb weakness
These features suggest an underlying neurologic infection rather than isolated facial nerve palsy.
Why This Case Matters
Facial paralysis is not always idiopathic—Lyme disease must remain in the differential diagnosis.
Misdiagnosis can delay treatment and allow progression to more severe neurologic disease.
Recognizing early warning signs can prevent prolonged disability.
Clinical Perspective
Lyme disease should be considered in patients presenting with facial palsy—especially when symptoms are atypical or progressive.
Even in regions considered “non-endemic,” clinicians should not rely solely on geographic assumptions.
Early testing and treatment may significantly improve outcomes.
Frequently Asked Questions
Can Lyme disease cause Bell’s palsy?
Yes. Lyme disease is a known cause of facial nerve palsy and may mimic idiopathic Bell’s palsy.
How can you tell the difference?
Clues include systemic symptoms, neurologic progression, and lack of response to steroids.
Does Lyme facial palsy require antibiotics?
Yes. Unlike idiopathic Bell’s palsy, Lyme-related facial palsy requires antimicrobial treatment.
Can Lyme disease cause more severe neurologic problems?
Yes. Untreated infection may progress to nerve pain, weakness, or widespread neurologic involvement.
Is Lyme disease possible outside endemic areas?
Yes. Cases may be underrecognized in regions previously considered low risk.
Related Reading
References
- Case report on Lyme neuroborreliosis with facial palsy and neurologic progression.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
