Bilateral Facial Palsy in Children: A Rare Lyme Disease Sign Often Mistaken for Bell’s Palsy

Bilateral facial palsy in children is rare but may signal serious systemic disease such as Lyme neuroborreliosis. A 10-year-old boy in southeastern Canada developed paralysis affecting both sides of his face after a summer fever and rash.

Facial paralysis caused by Lyme disease is often initially mistaken for Bell’s palsy, particularly when only one side of the face is affected. However, when paralysis occurs on both sides of the face simultaneously, clinicians must urgently evaluate for infectious or inflammatory causes.

Initial treatment with methylprednisolone and IVIG failed completely. Six days later, physicians diagnosed Lyme disease. Four weeks of intravenous ceftriaxone resolved his bilateral facial nerve palsy.

Brain MRI revealed that the infection affected seven cranial nerves—not only the facial nerve but also nerves responsible for eye movement, facial sensation, hearing, and swallowing. This extensive cranial neuropathy demonstrates how aggressively Lyme bacteria can invade the nervous system when disseminated infection goes unrecognized.

Why Bilateral Facial Palsy Requires Urgent Evaluation

Less than 2% of facial palsy cases are bilateral. “Unlike unilateral facial palsy, it is often caused by a serious underlying systemic disease and therefore warrants urgent medical intervention,” wrote Yang and Dalal in their article Bilateral Facial Palsy: A Clinical Approach.

When facial paralysis affects both sides of the face, idiopathic Bell’s palsy becomes unlikely. Bilateral involvement suggests infectious or inflammatory processes affecting the nervous system.

The Clinical Timeline

“A previously healthy 10-year-old boy presented in late August with a one-day history of bilateral facial palsy and an otherwise normal neurological examination,” wrote Piche-Renaud and colleagues.

Three weeks earlier he experienced a transient rash on his chest accompanied by fever. Although no tick bite was remembered, the family was aware of ticks in their region of southeastern Canada.

The three-week interval between rash and facial paralysis reflects the classic progression of neurologic Lyme disease, when Borrelia burgdorferi spreads through the bloodstream and invades the nervous system.

MRI Reveals Extensive Cranial Nerve Involvement

Brain MRI showed bilateral enhancement of cervical cranial nerve roots consistent with bilateral facial palsy.

The imaging also demonstrated involvement of multiple additional cranial nerves:

• Oculomotor nerve (III)
• Trigeminal nerve (V)
• Abducens nerve (VI)
• Facial nerve (VII)
• Vestibulocochlear nerve (VIII)
• Vagus nerve (X)
• Hypoglossal nerve (XII)

In total, seven cranial nerves were affected. While facial paralysis was obvious, inflammation in other nerves could affect eye movement, facial sensation, hearing, balance, swallowing, and tongue movement—demonstrating the severity of disseminated infection.

Treatment Failure Then Success

The child was initially treated with steroids and IVIG without improvement.

This lack of response provided an important diagnostic clue. Steroids and IVIG treat autoimmune or inflammatory causes of facial paralysis but do not treat bacterial infection.

Six days later Lyme disease was diagnosed. Four weeks of intravenous ceftriaxone resulted in complete resolution of the child’s bilateral facial nerve palsy.

The dramatic response to antibiotics confirmed the diagnosis of Lyme neuroborreliosis rather than idiopathic Bell’s palsy.

Frequently Asked Questions

What is bilateral facial palsy?
Bilateral facial palsy is paralysis affecting both sides of the face simultaneously. It occurs in fewer than 2% of facial palsy cases and often indicates serious systemic disease.

Can Lyme disease cause Bell’s palsy?
Yes. Lyme disease is a common cause of facial palsy in endemic areas and may initially be mistaken for Bell’s palsy.

Should children with bilateral facial palsy be tested for Lyme disease?
Yes. In endemic regions, bilateral facial palsy should prompt immediate Lyme disease testing even if no tick bite is recalled.

Why didn’t steroids or IVIG work?
Steroids and IVIG treat autoimmune or inflammatory disorders. They do not treat bacterial infections such as Lyme disease.

Can children recover from Lyme-related facial palsy?
Yes. With appropriate antibiotic treatment, children can recover fully. In this case, the child’s symptoms resolved after four weeks of IV ceftriaxone.

Clinical Takeaway

Bilateral facial palsy is a diagnostic red flag that should trigger urgent evaluation for systemic disease.

This case highlights how Lyme disease can produce extensive cranial nerve involvement when infection disseminates. Early recognition and appropriate antibiotic treatment are essential to prevent permanent neurologic injury.