What is the recommended treatment for a patient with active shingles?

Treatment of Active Shingles

For active shingles, initiate oral valacyclovir 1 gram three times daily for 7 days within 72 hours of rash onset, continuing treatment until all lesions have completely scabbed. 1, 2, 3

First-Line Oral Antiviral Therapy

Valacyclovir is the preferred first-line agent due to superior bioavailability and convenient dosing compared to acyclovir. 1, 2

• Valacyclovir 1 gram orally three times daily for 7 days is the standard regimen for uncomplicated herpes zoster 1, 2, 3
• Alternative: Acyclovir 800 mg orally five times daily for 7-10 days remains effective but requires more frequent dosing 1, 2, 3
• Alternative: Famciclovir 500 mg orally three times daily for 7 days offers comparable efficacy with convenient dosing 1, 4

Critical timing: 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, 5, 6 However, treatment beyond 72 hours may still provide benefit, particularly in immunocompromised patients or those with severe disease. 1

Treatment Duration and Endpoint

Continue antiviral therapy until all lesions have completely scabbed, not just for an arbitrary 7-day period. 1, 2

• In immunocompetent patients, lesions typically continue to erupt for 4-6 days with total disease duration of approximately 2 weeks 1
• Do not discontinue treatment at exactly 7 days if lesions are still forming or have not completely scabbed 1
• Immunocompromised patients may develop new lesions for 7-14 days and heal more slowly, requiring treatment extension well beyond 7-10 days 1

Escalation to Intravenous Therapy

Switch to intravenous acyclovir 5-10 mg/kg every 8 hours for severe or complicated disease: 1, 2

• Disseminated herpes zoster (multi-dermatomal involvement or visceral involvement) 1, 2
• Complicated facial zoster with suspected CNS involvement or severe ophthalmic disease 1
• Severely immunocompromised patients (HIV with CD4 <100, active chemotherapy, solid organ transplant recipients) 1
• Patients unable to tolerate oral therapy or with evidence of treatment failure 1, 2

Continue IV therapy for minimum 7-10 days and until clinical resolution is attained, then switch to oral therapy to complete the treatment course. 1, 2

Special Populations

Immunocompromised Patients

All immunocompromised patients with herpes zoster require antiviral treatment regardless of timing. 1, 2

• Consider intravenous acyclovir 10 mg/kg every 8 hours for severely immunocompromised hosts 1
• Temporary reduction in immunosuppressive medication should be considered in patients with disseminated or invasive herpes zoster 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

Facial/Ophthalmic Involvement

Facial zoster requires particular attention due to risk of cranial nerve complications. 1

• Initiate oral valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily within 72 hours of rash onset 1
• Continue treatment for 7-10 days until all lesions have scabbed 1
• Consider ophthalmology referral for suspected ocular involvement 5

Ramsay Hunt Syndrome (Herpes Zoster Oticus)

Initiate oral valacyclovir 1 gram three times daily for 7 days combined with systemic corticosteroids as soon as possible, ideally within 72 hours of symptom onset. 7

• Presents with vesicles on external ear canal and posterior auricle, severe otalgia, facial paralysis, loss of taste on anterior two-thirds of tongue, and decreased lacrimation 7
• Systemic corticosteroids should be added to antiviral therapy given facial nerve involvement 7

Role of Corticosteroids

Corticosteroids may be used as adjunctive therapy in select cases of severe, widespread shingles. 1

• Prednisone provides modest benefits in reducing acute pain but does not reduce the frequency of postherpetic neuralgia 8
• Prednisone should generally be avoided in immunocompromised patients due to increased risk of disseminated infection 1
• Prednisone use carries significant risks, particularly in elderly patients who are most susceptible to shingles 1

Common Pitfalls to Avoid

• Never use topical antivirals for shingles treatment—they are substantially less effective than systemic therapy 1, 2
• Do not delay treatment waiting for laboratory confirmation—diagnosis is clinical and treatment should begin immediately 7
• Do not discontinue treatment at exactly 7 days if lesions remain active—treatment duration should be guided by lesion healing, not calendar days 1
• Do not confuse short-course therapy designed for genital herpes (400mg TDS) with appropriate shingles dosing (800mg five times daily for acyclovir) 1

Monitoring During Treatment

• Monitor renal function at initiation and once or twice weekly during IV acyclovir therapy, with dose adjustments as needed for renal impairment 1
• If lesions fail to begin resolving within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 1
• For acyclovir-resistant cases, foscarnet 40 mg/kg IV every 8 hours is the treatment of choice 1, 2

Prevention After Recovery

The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes. 1, 2

• Vaccination can be considered after recovery to prevent future episodes 1
• Vaccination should ideally occur before initiating immunosuppressive therapies 1