What is the recommended treatment for a patient diagnosed with Herpes zoster?

Treatment of Herpes Zoster

For uncomplicated herpes zoster in immunocompetent patients, initiate oral valacyclovir 1 gram three times daily for 7-10 days, continuing until all lesions have completely scabbed. 1, 2

Treatment Algorithm Based on Disease Severity and Immune Status

Uncomplicated Herpes Zoster (Immunocompetent Patients)

First-line therapy:

• Valacyclovir 1000 mg orally three times daily for 7 days is the preferred first-line treatment due to superior bioavailability and convenient dosing compared to acyclovir 1, 2, 3
• Alternative: Acyclovir 800 mg orally five times daily for 7-10 days if valacyclovir is unavailable 1, 2, 4
• Alternative: Famciclovir 500 mg orally three times daily for 7 days offers equivalent efficacy with convenient dosing 1, 5

Critical timing considerations:

• Treatment must be initiated within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia 1, 6, 7
• Treatment initiated within 48 hours provides maximum benefit 1
• Some evidence suggests benefit even when started after 72 hours, though efficacy is reduced 2, 8

Treatment endpoint:

• Continue antiviral therapy until all lesions have completely scabbed, not just for an arbitrary 7-day period 1, 2
• Monitor for complete healing; treatment may need extension beyond 7-10 days if lesions remain active 1, 2

Disseminated or Invasive Herpes Zoster

Immediate escalation to intravenous therapy is mandatory for:

• Multi-dermatomal involvement (>3 dermatomes) 1, 9
• Visceral organ involvement 1, 9
• Central nervous system complications 1, 2
• Complicated ocular disease 1, 2

Intravenous acyclovir dosing:

• Standard dose: 5-10 mg/kg IV every 8 hours 1, 2, 9
• Higher dose (10 mg/kg) preferred for severely immunocompromised patients 1, 9
• Continue for minimum 7-10 days and until clinical resolution is attained 1, 2, 9
• Switch to oral therapy once clinical improvement occurs 2, 9

Immunosuppression management:

• Temporarily reduce or discontinue immunosuppressive medications in cases of disseminated or invasive disease if clinically feasible 1, 9
• Immunosuppression may be restarted after commencing anti-VZV therapy and complete resolution of skin vesicles 2, 9

Immunocompromised Patients (Uncomplicated Disease)

Treatment approach:

• Oral acyclovir or valacyclovir is appropriate for uncomplicated herpes zoster in immunocompromised patients 1
• Consider higher oral doses or extended treatment duration as immunocompromised patients develop new lesions for 7-14 days and heal more slowly 1, 2
• Monitor closely for dissemination and visceral complications 1, 2
• Without adequate antiviral therapy, some immunocompromised patients develop chronic ulcerations with persistent viral replication 1

High-risk populations requiring IV therapy:

• Patients on active chemotherapy (e.g., daratumumab, bortezomib, melphalan) 1
• Multiple myeloma patients 1
• HIV-infected patients with severe disease 1
• Solid organ transplant recipients with disseminated disease 1

Special Populations and Considerations

Facial/ophthalmic involvement:

• Requires particular urgency due to risk of ophthalmic and cranial nerve complications 1
• Initiate valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily within 72 hours 1
• Consider IV acyclovir for complicated facial zoster with suspected CNS involvement or severe ophthalmic disease 1

Renal impairment:

• Dosage adjustment is mandatory to prevent acute renal failure 1, 4
• Monitor renal function closely during IV acyclovir therapy 1
• Specific dose adjustments required based on creatinine clearance 1, 2

Elderly patients (≥50 years):

• Show greater benefit from antiviral therapy 1, 4
• At highest risk for postherpetic neuralgia 1, 7
• Acyclovir plasma concentrations are higher due to age-related changes in renal function; dosage reduction may be required with underlying renal impairment 4

Acyclovir-Resistant Cases

For proven or suspected acyclovir resistance:

• Foscarnet 40 mg/kg IV every 8 hours until clinical resolution 1, 2
• All acyclovir-resistant strains are also resistant to valacyclovir, and most are resistant to famciclovir 1
• Resistance is extremely rare in immunocompetent patients but occurs more frequently in immunocompromised patients receiving prolonged suppressive therapy 1
• Monitor for acyclovir resistance if lesions persist despite treatment 1

Critical Monitoring Parameters

During IV acyclovir therapy:

• Monitor renal function at initiation and once or twice weekly during treatment 1, 4
• Assess for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients receiving high-dose therapy 1
• Maintain adequate hydration to reduce risk of renal dysfunction 4, 6

Treatment failure indicators:

• If lesions fail to begin resolving within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 1

Common Pitfalls to Avoid

Do NOT use topical antivirals:

• Topical antiviral therapy is substantially less effective than systemic therapy and is not recommended 1, 2

Do NOT use corticosteroids routinely:

• Prednisone may be used as adjunctive therapy in select cases of severe, widespread shingles, but carries significant risks particularly in elderly patients 1
• Corticosteroids are contraindicated in immunocompromised patients due to increased risk of disseminated infection 1

Do NOT discontinue treatment at exactly 7 days:

• Treatment endpoint is complete scabbing of all lesions, not calendar days 1, 2
• Short-course therapy designed for genital herpes is inadequate for VZV infection 1

Prevention and Vaccination

Recombinant zoster vaccine (Shingrix):

• Recommended for all adults aged ≥50 years regardless of prior herpes zoster episodes 1, 2
• Provides >90% efficacy in preventing future recurrences 1
• Should be administered after recovery from current episode 1
• Ideally given before initiating immunosuppressive therapies 1

Post-exposure prophylaxis:

• Varicella zoster immunoglobulin (VZIG) within 96 hours of exposure for varicella-susceptible patients 1, 2
• If immunoglobulin unavailable or >96 hours have passed, 7-day course of oral acyclovir beginning 7-10 days after exposure 1, 2

Infection Control

Patients with active herpes zoster:

• Avoid contact with susceptible individuals until all lesions have crusted 1
• Lesions are contagious to individuals who have not had chickenpox or vaccination 1
• Cover lesions with clothing or dressings to minimize transmission risk 1
• For disseminated zoster, implement both airborne and contact precautions 1