What is the recommended treatment for a patient 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 within 72 hours of rash onset, continuing treatment until all lesions have completely scabbed. 1, 2

Treatment Algorithm Based on Disease Severity and Patient Population

Uncomplicated Herpes Zoster (Immunocompetent Patients)

First-line options:

• Valacyclovir 1 gram orally three times daily for 7-10 days 1, 2
• Famciclovir 500 mg orally three times daily for 7 days 3, 4
• Acyclovir 800 mg orally five times daily for 7-10 days 1, 2

Valacyclovir and famciclovir offer superior bioavailability and more convenient dosing schedules compared to acyclovir, which requires five-times-daily administration. 1, 4 The critical endpoint is complete scabbing of all lesions, not an arbitrary 7-day duration—treatment must continue beyond 7 days if lesions remain active. 1, 2

Timing is critical: Antiviral therapy must be initiated within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia. 1, 4 Earlier initiation within 48 hours provides maximum benefit. 1

Disseminated or Invasive Herpes Zoster

Intravenous acyclovir 10 mg/kg every 8 hours is mandatory for: 1, 5

• Multi-dermatomal involvement
• Visceral organ involvement
• Severely immunocompromised patients (chemotherapy, HIV, transplant recipients)
• CNS complications
• Complicated ophthalmic disease

Continue IV therapy for minimum 7-10 days and until clinical resolution is attained (all lesions completely scabbed, no new lesions forming, resolution of visceral complications). 1, 5 Switch to oral therapy once clinical improvement occurs. 2, 5

Immunosuppression management: Temporarily reduce or discontinue immunosuppressive medications in severe disseminated cases; restart after commencing anti-VZV therapy and skin vesicle resolution. 1, 5

Special Populations Requiring Heightened Vigilance

Immunocompromised patients (any degree):

• All require antiviral treatment regardless of timing beyond 72 hours 1
• Higher risk of dissemination (10-20% without prompt therapy) 5
• May require extended treatment duration beyond 7-10 days as lesions develop over longer periods (7-14 days) and heal more slowly 1
• Monitor closely for visceral complications and dissemination 1, 5

Facial/ophthalmic involvement:

• Requires urgent treatment due to risk of vision-threatening complications and cranial nerve involvement 1
• Consider IV acyclovir for complicated facial zoster with suspected CNS involvement 1

Patients >50 years:

• Systemic antiviral therapy urgently indicated to prevent postherpetic neuralgia 6

Critical Treatment Caveats

Do not use topical antivirals—they are substantially less effective than systemic therapy and are not recommended. 1, 2

Monitor renal function closely during IV acyclovir therapy with dose adjustments for renal impairment; assess for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients receiving high-dose therapy. 1

Acyclovir-resistant cases: If lesions persist despite adequate treatment, suspect resistance and switch to foscarnet 40 mg/kg IV every 8 hours until clinical resolution. 1, 2 All acyclovir-resistant strains are also resistant to valacyclovir, and most to famciclovir. 1

Post-Exposure Prophylaxis

For varicella-susceptible patients exposed to active varicella zoster infection:

• Varicella zoster immunoglobulin within 96 hours of exposure (high-risk individuals: pregnant women, immunocompromised patients, neonates) 1, 2
• If immunoglobulin unavailable or >96 hours elapsed: 7-day course of oral acyclovir beginning 7-10 days after exposure 1, 2

Prevention

The recombinant zoster vaccine (Shingrix) is recommended for all adults ≥50 years regardless of prior herpes zoster episodes, ideally administered before initiating immunosuppressive therapies. 1, 2 This is the most effective strategy for preventing herpes zoster and postherpetic neuralgia. 7

Pain Management Considerations

Appropriately dosed analgesics combined with neuroactive agents (e.g., amitriptyline, gabapentin, pregabalin) should be given alongside antiviral therapy for acute zoster pain. 6, 8 Corticosteroids may provide modest benefits in reducing acute pain but have no essential effect on preventing postherpetic neuralgia. 6, 8