What is the recommended treatment for shingles (herpes zoster) after 1 week?

Treatment for Shingles After 1 Week

Antiviral therapy should still be initiated for herpes zoster presenting after 1 week if new lesions are still forming or if lesions have not fully crusted, as treatment can reduce viral replication, prevent complications, and shorten the duration of pain. 1, 2

When to Treat Beyond 72 Hours

While the traditional teaching emphasizes starting antivirals within 72 hours of rash onset, the evidence supports a more nuanced approach:

• Treatment remains beneficial when started after 72 hours if active viral replication is ongoing, indicated by new vesicle formation or incomplete crusting of existing lesions 3, 2
• A large observational study demonstrated that starting valacyclovir later than 72 hours after rash onset did not significantly reduce its beneficial effect on duration of zoster-associated pain 3
• In immunocompromised patients, antiviral therapy should be instituted if presentation occurs within 1 week of rash onset or any time before full crusting of lesions 2

Recommended Antiviral Regimens

For Immunocompetent Patients with Uncomplicated Shingles:

First-line oral options (continue until all lesions have scabbed):

• Valacyclovir 1000 mg three times daily for 7 days 1, 3
• Acyclovir 800 mg five times daily for 7 days 1, 4
• Famciclovir 500 mg three times daily for 7 days 4, 3

Valacyclovir offers superior convenience with three-times-daily dosing versus acyclovir's five-times-daily regimen, which may improve adherence 3. An alternative valacyclovir regimen of 1.5 g twice daily has also demonstrated safety and efficacy 5.

For Immunocompromised Patients:

• Most patients with localized disease can be treated with oral antivirals (valacyclovir, famciclovir, or acyclovir) with close outpatient follow-up 2
• Intravenous acyclovir is reserved for: disseminated varicella zoster infection, ophthalmic involvement, severe immunosuppression, or inability to take oral medications 1, 2
• Consider temporary reduction in immunosuppressive medications for disseminated or invasive disease 1

Critical Treatment Endpoints

Continue antiviral therapy at least until all lesions have scabbed 6, 1. This is the key clinical endpoint, not an arbitrary 7-day duration. If lesions remain active beyond 7 days, treatment should continue 6.

Role of Corticosteroids

The evidence for corticosteroids is mixed and their benefit is modest at best:

• A large randomized trial found that adding prednisolone (40 mg daily, tapered over 3 weeks) to acyclovir provided only slight benefits during the acute phase with faster healing and greater pain reduction on days 7-14, but no reduction in postherpetic neuralgia 7
• Steroid recipients reported more adverse events 7
• Corticosteroids should generally be avoided in immunocompromised patients due to increased risk of disseminated infection 1

Special Considerations

Disseminated or Invasive Disease:

• Requires intravenous acyclovir with temporary reduction in immunosuppression if applicable 1
• Treatment continues at least until all lesions have scabbed 1

Ophthalmic Involvement:

• Warrants ophthalmology referral due to risk of serious complications 4
• Requires systemic antiviral therapy, not topical agents 1

Acyclovir-Resistant Cases:

• Foscarnet is the drug of choice for acyclovir-resistant herpes zoster, typically seen in severely immunocompromised patients 2

Common Pitfalls to Avoid

• Do not withhold antivirals simply because 72 hours have passed if lesions are still forming or not fully crusted 3, 2
• Do not rely on topical antivirals, which are substantially less effective than systemic therapy 1
• Do not delay treatment waiting for laboratory confirmation in typical presentations; diagnosis is clinical 1
• Do not assume a 7-day course is always sufficient; treatment duration should be guided by lesion healing, not calendar days 6, 1