What is the recommended management for a patient presenting with herpes zoster?

Management of Herpes Zoster

For immunocompetent adults with herpes zoster, initiate oral valacyclovir 1 gram three times daily for 7 days (or acyclovir 800 mg five times daily for 7-10 days) within 72 hours of rash onset, continuing treatment until all lesions have completely scabbed. 1, 2, 3

Antiviral Therapy: The Foundation of Treatment

First-Line Oral Regimens for Immunocompetent Patients

Valacyclovir is preferred over acyclovir due to superior bioavailability (three- to fivefold higher), less frequent dosing that improves adherence, and faster resolution of zoster-associated pain. 4, 5

• Valacyclovir 1000 mg orally three times daily for 7 days is the optimal regimen, significantly accelerating pain resolution (median 38 days vs 51 days with acyclovir) and reducing postherpetic neuralgia duration. 4, 2

• Acyclovir 800 mg orally five times daily for 7-10 days remains an effective alternative when valacyclovir is unavailable, though it requires more frequent dosing. 1, 3

• Famciclovir 500 mg three times daily for 7 days demonstrates similar efficacy to valacyclovir and is another acceptable first-line option. 5, 1

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 However, treatment started beyond 72 hours may still provide benefit, particularly for pain reduction, and should not be withheld. 5

Continue antiviral therapy until all lesions have completely scabbed, not just for an arbitrary 7-day period—this is the key clinical endpoint. 1, 6 If lesions remain active beyond 7 days, extend treatment duration accordingly. 1

Intravenous Therapy for Severe or Complicated Disease

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

• Disseminated herpes zoster (multi-dermatomal involvement or visceral disease) 1
• Immunocompromised patients, including those on chemotherapy, with HIV, or receiving immunosuppressive medications 1
• Central nervous system complications (encephalitis, meningitis) 1
• Complicated ophthalmic zoster with suspected CNS involvement 1
• Severe disease requiring hospitalization 8

Continue IV therapy for at least 7-10 days and until clinical resolution is attained (all lesions scabbed). 1 Monitor renal function closely during IV therapy with dose adjustments for renal impairment. 1

Special Populations and Dose Adjustments

Immunocompromised Patients

For immunocompromised patients with uncomplicated herpes zoster, oral valacyclovir or acyclovir is appropriate, but consider IV acyclovir 10 mg/kg every 8 hours given the high risk of dissemination. 1

Temporarily reduce immunosuppressive medications when feasible in cases of disseminated or invasive herpes zoster. 1

Renal Impairment

Mandatory dose adjustments are required to prevent acute renal failure:

• Creatinine clearance 30-49 mL/min: Valacyclovir 1000 mg twice daily 2
• Creatinine clearance 10-29 mL/min: Valacyclovir 1000 mg once daily 2
• Creatinine clearance <10 mL/min: Valacyclovir 500 mg once daily 2

Similar adjustments apply to acyclovir and famciclovir based on creatinine clearance. 3, 1

Elderly Patients (≥50 Years)

Valacyclovir 1000 mg three times daily for 7 days is particularly beneficial in patients ≥50 years, who show greater benefit from early antiviral therapy and are at highest risk for postherpetic neuralgia. 4, 3

Assess renal function before initiating therapy, as age-related decline in renal function necessitates dose adjustment in many elderly patients. 3

Adjunctive Therapies and What to Avoid

Corticosteroids: Limited Role

Corticosteroids are NOT routinely recommended for herpes zoster management. 9 While prednisolone may slightly accelerate rash healing and reduce acute pain in the first 7-14 days, it provides no benefit in preventing postherpetic neuralgia and increases adverse events. 9

Avoid corticosteroids entirely in:

• Immunocompromised patients (increased risk of disseminated infection) 1
• Patients with poorly controlled diabetes, severe osteoporosis, or history of steroid-induced complications 1

Topical Therapies: Not Recommended

Topical antiviral therapy is substantially less effective than systemic therapy and should not be used. 1 Topical anesthetics provide minimal benefit during the acute phase. 1

Acute Pain Management

For acute zoster pain during the active rash phase:

• Opioid analgesics may be used for severe acute pain 10
• Gabapentin or pregabalin can be initiated early if pain is severe 6
• Tricyclic antidepressants (e.g., amitriptyline) may provide adjunctive pain relief 10

Do NOT prescribe opioids as first-line agents for long-term management of postherpetic neuralgia. 6

Prevention of Postherpetic Neuralgia

Early antiviral therapy with valacyclovir or famciclovir is the only proven intervention to reduce the risk and duration of postherpetic neuralgia. 7, 4 Valacyclovir reduces the proportion of patients with pain persisting at 6 months from 25.7% to 19.3%. 4

If postherpetic neuralgia develops (pain persisting >30 days after lesion healing):

• First-line: Gabapentin titrated to 2400 mg/day in divided doses (NNT 4.39) 6
• Second-line: Pregabalin (NNT 4.93) or tricyclic antidepressants (NNT 2.64) 6
• Topical: Capsaicin 8% patch (single 30-minute application after pre-treatment with 4% lidocaine for 60 minutes) or lidocaine patches (NNT 2) 6

Infection Control and Prevention

Patients with active herpes zoster are contagious to varicella-susceptible individuals (those who have not had chickenpox or vaccination) until all lesions have crusted. 1 Advise patients to avoid contact with pregnant women, immunocompromised individuals, and infants until lesions are fully scabbed.

Varicella-zoster immunoglobulin (VZIG) within 96 hours of exposure is recommended for varicella-susceptible pregnant women, immunocompromised patients, and other high-risk individuals exposed to active herpes zoster. 1

Vaccination After Recovery

The recombinant zoster vaccine (Shingrix) is strongly recommended for all adults ≥50 years, regardless of prior herpes zoster episodes, to prevent future recurrences. 1, 7 The vaccine provides >90% efficacy in preventing future herpes zoster and should be administered after recovery from the current episode. 1

Acyclovir-Resistant Cases

If lesions fail to improve after 7-10 days of appropriate antiviral therapy, suspect acyclovir resistance and obtain viral culture with susceptibility testing. 1

For proven acyclovir-resistant herpes zoster: Foscarnet 40 mg/kg IV every 8 hours until clinical resolution. 1 All acyclovir-resistant strains are also resistant to valacyclovir, and most are resistant to famciclovir. 1

Common Pitfalls to Avoid

• Do not delay treatment waiting for laboratory confirmation—herpes zoster is a clinical diagnosis in immunocompetent patients with typical presentation 1
• Do not stop antiviral therapy at exactly 7 days if lesions are still forming or have not completely scabbed 1
• Do not use topical antivirals as they are substantially less effective than systemic therapy 1
• Do not prescribe acyclovir 400 mg three times daily—this dose is only appropriate for genital herpes, not herpes zoster 1
• Do not use live-attenuated zoster vaccine (Zostavax) in immunocompromised patients—use recombinant vaccine (Shingrix) instead 1