How should shingles (herpes zoster) be treated in adults, including antiviral therapy, pain control, post‑herpetic neuralgia management, isolation precautions, and vaccination recommendations?

Treatment of Shingles (Herpes Zoster) in Adults

Start oral antiviral therapy within 72 hours of rash onset with valacyclovir or famciclovir as first-line agents, combined with appropriate analgesics for pain control, and ensure vaccination with recombinant zoster vaccine (Shingrix) for prevention in adults ≥50 years. 1, 2

Antiviral Therapy

Timing and Indications

• Initiate antiviral therapy within 72 hours of rash onset to accelerate cutaneous healing, reduce acute pain severity, and prevent complications 1, 3
• Treatment within 48 hours is optimal, though benefit extends to 72 hours 3
• Urgent indications requiring immediate antiviral therapy include:
  • All patients >50 years of age 3
  • Herpes zoster involving head/neck area, especially zoster ophthalmicus 3
  • Immunocompromised patients at any age 3, 4
  • Severe disease on trunk or extremities 3
  • Patients with severe atopic dermatitis or eczema 3

Preferred Antiviral Agents

• Valacyclovir 1.5 g twice daily for 7 days is preferred due to superior bioavailability and improved compliance compared to acyclovir 5, 4
• Famciclovir (dose per standard protocols) offers similar efficacy with less frequent dosing than acyclovir 1, 4
• Acyclovir remains FDA-approved but requires more frequent dosing (5 times daily), making it less practical 1, 3
• All three agents demonstrate equivalent efficacy in reducing zoster-associated pain and accelerating healing when given within the therapeutic window 6, 3

Special Populations

• Immunocompromised patients: Use oral antivirals for uncomplicated cases, but monitor closely for cutaneous or visceral dissemination requiring intravenous therapy 6, 4
• Pregnant women: Intravenous acyclovir should be considered for serious complications like pneumonia, though routine oral use is not recommended 1

Pain Management

Acute Pain Control

• Combine appropriately dosed analgesics with neuroactive agents (e.g., amitriptyline) alongside antiviral therapy to achieve painlessness 3
• Corticosteroids may shorten acute pain duration but do not prevent postherpetic neuralgia and carry significant risks in elderly patients 2, 3
• Avoid systemic corticosteroids in older adults with contraindications including poorly controlled diabetes, labile hypertension, glaucoma, or peptic ulcer disease 2

Postherpetic Neuralgia (PHN) Management

• First-line pharmacological treatments for PHN include tricyclic antidepressants (amitriptyline, nortriptyline, doxepin) 2
• Alternative systemic agents include anticonvulsants (gabapentin, pregabalin) 4
• Topical lidocaine patches provide localized relief 4
• Critical caveat: Antiviral therapy does not influence established PHN, though early treatment may reduce its incidence 6, 4

Isolation Precautions

• Implement contact precautions until all lesions are crusted over, as active lesions contain infectious varicella-zoster virus 4
• Routine hand hygiene and appropriate use of personal protective equipment are essential 4
• Susceptible individuals (no history of chickenpox or vaccination, seronegative for VZV) should avoid exposure to patients with active shingles 1

Vaccination Recommendations

Primary Prevention Strategy

• Recombinant zoster vaccine (Shingrix) is strongly preferred for all adults ≥50 years, with 97.2% efficacy against shingles, 91.3% efficacy in those ≥70 years, and 88.8% efficacy against PHN 2
• Protection maintained >83% for up to 8 years 2
• Immunocompromised adults ≥19 years should receive vaccination due to elevated reactivation risk 7

Alternative Vaccine

• Zoster vaccine live (Zostavax) is less effective (51.3% efficacy against shingles, 66.5% against PHN in those ≥60 years) with significant waning over time 2

Post-Infection Vaccination

• Vaccination is recommended even after a previous episode of herpes zoster for all individuals ≥60 years with no contraindications 4

Complications Requiring Urgent Consultation

• Approximately 50% of patients with herpes zoster ophthalmicus develop ocular complications (conjunctivitis, keratitis, uveitis), necessitating urgent ophthalmologic consultation 7
• Monitor immunocompromised patients for signs of dissemination requiring escalation to intravenous antiviral therapy 6, 4

Key Clinical Pitfalls to Avoid

• Do not delay antiviral therapy beyond 72 hours of rash onset, as efficacy diminishes significantly 3, 4
• Do not rely on corticosteroids to prevent PHN—only valacyclovir, famciclovir, and vaccination have proven preventive benefit 4
• Do not use acyclovir prophylactically in healthy individuals after VZV exposure; vaccination is the appropriate intervention 1
• Do not assume immunity eliminates latent virus—VZV persists permanently in sensory ganglia, and cell-mediated immunity only suppresses reactivation, never eradicates the virus 8