What is the most likely diagnosis and acute treatment plan for a 57‑year‑old patient with unilateral maxillary‑mandibular vesicular rash, oral mucosal ulceration, erythematous swollen ear with vesicles, severe facial and temporal pain, no fever or facial nerve weakness, and a shingles vaccination 10 years ago?

Diagnosis: Ramsay Hunt Syndrome (Herpes Zoster Oticus)

This patient has Ramsay Hunt syndrome—varicella-zoster virus reactivation affecting the geniculate ganglion—and requires immediate oral antiviral therapy with valacyclovir 1000 mg three times daily for 7-10 days, continuing until all lesions have completely scabbed. 1

Clinical Reasoning

The constellation of findings is pathognomonic for Ramsay Hunt syndrome:

• Unilateral vesicular rash on the ear (red, swollen with vesicles), face (maxillary and mandibular distribution), and oral mucosa (gum ulcer) in a dermatomal pattern 2, 1
• Severe otalgia and facial pain (7-8/10 severity) with temporal involvement and waves of neuropathic pain 1, 3
• Oral mucosal ulceration (mouth ulcers, gum involvement) indicating trigeminal nerve distribution 4, 5
• Absence of facial nerve weakness (no facial palsy documented, though this can develop later) 2, 5
• Prior shingles vaccination 10 years ago does not prevent reactivation, as vaccine efficacy wanes and does not eliminate latent VZV 1, 6

The maculopapular and vesicular rash with severe unilateral pain affecting the ear canal, face, and oral cavity confirms VZV reactivation involving the geniculate ganglion and trigeminal nerve branches. 2, 1, 3

Immediate Treatment Plan

First-Line Antiviral Therapy

Initiate oral valacyclovir 1000 mg three times daily immediately, even though symptom onset was Saturday (assuming presentation within 72 hours of rash onset). 1, 4, 7

• Alternative option: Famciclovir 500 mg three times daily if valacyclovir is unavailable 1
• Less preferred: Acyclovir 800 mg five times daily (requires more frequent dosing, lower bioavailability) 1, 8
• Treatment duration: Continue for 7-10 days AND until all lesions have completely scabbed—do not stop at exactly 7 days if active vesicles remain 1, 5

Adjunctive Corticosteroid Therapy

Add oral prednisone 60 mg daily for 7 days (or equivalent dexamethasone) to improve facial nerve recovery outcomes, as this patient has significant cranial nerve involvement. 1, 4, 5

• Corticosteroids combined with antivirals lead to facial nerve recovery in >75% of cases when started early 7
• Contraindications to assess: Poorly controlled diabetes, severe osteoporosis, history of steroid-induced psychosis, active infection requiring systemic antibiotics 1

Pain Management

Prescribe gabapentin 300 mg three times daily or pregabalin 75-150 mg twice daily for neuropathic pain control, titrating upward as needed. 4

• Acute pain relief: Acetaminophen 1000 mg every 6 hours and/or ibuprofen 600 mg every 8 hours for breakthrough pain 1
• Topical measures: Cold compresses to affected areas for symptomatic relief 1
• Avoid: Topical antivirals (substantially less effective than systemic therapy) 1

Skin and Wound Care

• Keep lesions clean and dry; cover with loose dressing to prevent secondary bacterial infection 1
• Avoid applying products to active vesicles; emollients may be used only after lesions have crusted 1
• Monitor for secondary bacterial infection given the extensive facial involvement and oral ulceration 4

Urgent Ophthalmology Referral

Obtain same-day or next-day ophthalmology evaluation because the maxillary distribution raises concern for potential ophthalmic (V1) involvement, which can cause vision-threatening complications. 1, 3

• Examine for Hutchinson's sign (vesicles on tip/side of nose indicating nasociliary branch involvement) 1
• Assess for conjunctival injection, keratitis, or uveitis 1

Escalation Criteria for Intravenous Therapy

Switch to IV acyclovir 10 mg/kg every 8 hours if:

• Lesions involve ≥3 dermatomes (disseminated disease) 1
• New neurologic symptoms develop (facial weakness, hearing loss, vertigo, altered mental status) 1, 5
• Immunocompromised status is identified (HIV, active chemotherapy, chronic immunosuppression) 1, 6
• Lesions fail to improve or continue forming after 7-10 days of oral therapy 1
• Signs of visceral involvement appear (hepatitis, pneumonitis, encephalitis) 1

Monitoring and Follow-Up

• Reassess in 48-72 hours to confirm lesion stabilization and pain improvement 1
• Continue treatment until all lesions have scabbed—this is the key endpoint, not an arbitrary 7-day duration 1, 5
• Monitor for facial nerve palsy development, which can appear after rash onset in Ramsay Hunt syndrome 7, 5
• Assess hearing at follow-up, as auditory nerve involvement can cause sensorineural hearing loss 2, 5

Infection Control

Instruct the patient to avoid contact with pregnant women, immunocompromised individuals, and anyone without varicella immunity until all lesions have crusted, as active lesions can transmit VZV to susceptible individuals. 1

Common Pitfalls to Avoid

• Do not delay treatment waiting for laboratory confirmation—this is a clinical diagnosis requiring immediate empiric therapy 1, 3
• Do not stop antivirals at exactly 7 days if lesions remain active; continue until complete scabbing 1
• Do not use topical acyclovir as primary therapy (ineffective for systemic VZV infection) 1
• Do not dismiss the prior shingles vaccine as protective—vaccine efficacy wanes and reactivation can still occur 1, 6
• Do not overlook ophthalmic involvement—facial distribution warrants ophthalmology evaluation 1, 3

Future Prevention

After complete recovery, administer recombinant zoster vaccine (Shingrix) in a 2-dose series to prevent future VZV reactivation, as it provides >90% efficacy regardless of prior herpes zoster episodes. 1