What is the most likely diagnosis and recommended acute management for a patient with left‑sided peripheral facial palsy, left ear pain, periauricular swelling, a mildly erythematous tympanic membrane, and normal blood pressure?

Ramsay Hunt Syndrome (Herpes Zoster Oticus)

This patient has Ramsay Hunt syndrome until proven otherwise, and requires immediate treatment with combination antiviral therapy (acyclovir or valacyclovir) plus corticosteroids to prevent permanent facial nerve damage. 1

Clinical Diagnosis

The constellation of symptoms—progressive deep tearing ear pain, ear canal inflammation (mildly erythematous tympanic membrane with periauricular swelling), and acute unilateral facial nerve paralysis—is pathognomonic for Ramsay Hunt syndrome. 1 This is a reactivation of varicella zoster virus (VZV) in the geniculate ganglion. 2

Facial weakness with ear pain is a red flag for VZV infection rather than simple bacterial otitis externa or Bell's palsy. 1 The American Academy of Otolaryngology-Head and Neck Surgery emphasizes that this combination should immediately trigger consideration of Ramsay Hunt syndrome even before vesicles appear. 1

Key Diagnostic Features to Document Now:

• Examine the pinna, external ear canal, and posterior auricular region meticulously for vesicular lesions—these may not be present initially but can appear within 24-72 hours. 1, 2
• Perform a complete facial nerve examination documenting the extent of paresis: check eye closure strength, forehead wrinkling, smile symmetry, and nasolabial fold depth. 1
• Test for hearing loss and vestibular symptoms (vertigo, nystagmus), as Ramsay Hunt syndrome commonly causes sensorineural hearing loss. 1
• The intact but erythematous tympanic membrane helps distinguish this from acute otitis media with facial palsy—pneumatic otoscopy would show normal tympanic membrane mobility in Ramsay Hunt syndrome versus reduced mobility in otitis media. 3

Immediate Management Protocol

1. Antiviral Therapy (Start Within 72 Hours of Symptom Onset)

Initiate acyclovir or valacyclovir immediately—delay beyond 72 hours significantly reduces efficacy in preventing permanent facial nerve damage. 1 The American Academy of Otolaryngology-Head and Neck Surgery recommends:

• Valacyclovir 1000 mg three times daily for 7 days (preferred for better bioavailability), OR
• Acyclovir 800 mg five times daily for 7 days 1

2. Corticosteroid Therapy

Add prednisone to improve facial nerve recovery outcomes—combination therapy is superior to antivirals alone. 1 Standard dosing:

• Prednisone 60-80 mg daily for 5-7 days, then taper over 10 days total 1

3. Eye Protection (Critical to Prevent Corneal Injury)

Since the left eye isn't blinking, immediate eye protection is mandatory to prevent corneal abrasion, ulceration, and potential vision loss. 1

• Artificial tears every 1-2 hours while awake 1
• Lubricating ointment at bedtime 1
• Eye patch or moisture chamber at night 1
• Consider ophthalmology referral within 24-48 hours if complete eye closure is absent 1

4. Pain Management

Severe neuropathic pain requires appropriate analgesics—the deep tearing ear pain described is characteristic of VZV neuralgia. 1

• Gabapentin 300 mg three times daily (titrate up to 900-1800 mg/day) OR pregabalin 75 mg twice daily for neuropathic pain 1
• NSAIDs or acetaminophen for additional analgesia 3
• Avoid opioids as first-line given the neuropathic nature of the pain 1

Critical Differential Diagnosis Considerations

Why This Is NOT Simple Otitis Externa:

Uncomplicated acute otitis externa does not cause facial nerve paralysis. 3 The American Academy of Otolaryngology-Head and Neck Surgery guidelines state that diffuse otitis externa presents with tragal tenderness, ear canal edema, and erythema, but facial nerve involvement indicates either necrotizing otitis externa (in diabetic/immunocompromised patients) or viral infection (Ramsay Hunt syndrome). 3

Why This Is NOT Bell's Palsy:

Bell's palsy is a diagnosis of exclusion that requires absence of identifiable cause, particularly absence of ear pain and ear canal findings. 3 The presence of ear pain, periauricular swelling, and tympanic membrane erythema excludes idiopathic Bell's palsy. 3, 1

Why This Is NOT Acute Otitis Media with Facial Palsy:

While acute otitis media can rarely cause facial palsy (particularly in children), the intact tympanic membrane with only mild erythema argues against middle ear infection. 4, 5 Acute otitis media causing facial palsy typically shows moderate-to-severe tympanic membrane bulging, middle ear effusion, and reduced tympanic membrane mobility on pneumatic otoscopy. 3

Common Pitfalls to Avoid

1. Waiting for vesicles to appear before starting treatment—vesicles may be absent initially or never develop (zoster sine herpete). Treatment must begin based on clinical presentation alone. 1, 2

2. Treating as simple otitis externa with topical antibiotics only—this will not address the underlying VZV infection and risks permanent facial nerve damage. 1

3. Delaying antiviral therapy beyond 72 hours—efficacy drops dramatically after this window. 1

4. Neglecting eye protection—corneal complications can occur within 24-48 hours of incomplete eye closure. 1

5. Failing to assess for diabetes or immunocompromised state—these patients are at higher risk for necrotizing otitis externa, which can also present with facial palsy and requires different management (surgical debridement plus systemic antipseudomonal antibiotics). 3

Follow-Up and Prognosis

Reassess within 48-72 hours to evaluate treatment response and document progression or improvement of facial nerve function. 3, 1 Patients with complete facial paralysis (as this patient has with absent eye blinking) have worse prognosis than those with incomplete paresis—only 60-70% achieve complete recovery even with optimal treatment. 6 If no improvement occurs within 2-3 weeks, consider referral to otolaryngology for electrodiagnostic testing (electroneuronography) to assess nerve degeneration. 3, 6