Management of Herpes Zoster (Shingles)
For adults with herpes zoster, initiate oral valacyclovir 1000 mg three times daily or famciclovir 500 mg three times daily within 72 hours of rash onset, continuing until all lesions have completely scabbed, and combine with gabapentin for acute neuropathic pain management. 1
Antiviral Therapy: The Foundation of Treatment
Timing Is Critical
- Start antiviral therapy within 72 hours of rash onset to achieve optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia 1, 2, 3
- Treatment initiated within 48 hours provides maximum benefit, but the 72-hour window remains the standard cutoff 1
- Even after 72 hours, treatment may still be warranted in patients with new lesion formation, immunocompromise, or complications 1
First-Line Oral Antiviral Regimens (Immunocompetent Adults)
Preferred agents (choose one):
- Valacyclovir 1000 mg orally three times daily for 7–10 days 1, 2, 3
- Famciclovir 500 mg orally three times daily for 7–10 days 1, 2, 3
- Acyclovir 800 mg orally five times daily for 7–10 days (requires more frequent dosing but equally effective) 1, 2, 3
Valacyclovir and famciclovir offer superior bioavailability and more convenient dosing compared to acyclovir, potentially improving adherence 1, 3. All three agents demonstrate equivalent efficacy and safety profiles 2, 3.
Treatment Duration: Until Complete Scabbing
- Continue antiviral therapy until all lesions have completely scabbed, not just for an arbitrary 7-day period 1
- Do not discontinue at exactly 7 days if lesions are still forming or have not fully crusted 1
- Immunocompromised patients may require treatment extension well beyond 7–10 days as their lesions develop over longer periods (7–14 days) and heal more slowly 1
Indications for Intravenous Acyclovir
Switch to IV acyclovir 10 mg/kg every 8 hours when any of the following are present 1:
- Disseminated herpes zoster (≥3 dermatomes, visceral involvement, or hemorrhagic lesions)
- Severe immunosuppression (active chemotherapy, HIV with low CD4 count, organ transplant)
- CNS complications (encephalitis, meningitis, Guillain-Barré syndrome)
- Complicated ocular or facial disease with suspected cranial nerve involvement
- Lack of clinical improvement after 7–10 days of appropriate oral therapy (suspect resistance)
- Inability to absorb oral medication
Continue IV therapy for a minimum of 7–10 days and until clinical resolution is attained 1.
Pain Management: A Dual Approach
Acute Neuropathic Pain (During Active Infection)
First-line systemic therapy:
- Gabapentin, titrated in divided doses up to 2400 mg per day, is the recommended first-line agent for acute zoster-associated neuropathic pain 1
- Gabapentin improves sleep quality but causes somnolence in approximately 80% of patients—counsel accordingly 1
- Pregabalin may be added for patients whose pain remains uncontrolled with gabapentin alone 1
Adjunctive analgesics:
- Over-the-counter acetaminophen and ibuprofen provide relief for acute pain 1
- Application of topical ice or cold packs can reduce pain and swelling during the acute phase 1
Avoid these pitfalls:
- Topical anesthetics provide minimal benefit and are not recommended as primary therapy for acute zoster pain 1
- Topical antiviral therapy is substantially less effective than systemic therapy and should not be used 1
Role of Corticosteroids: Use With Caution
- Prednisone may be used as adjunctive therapy to antivirals in select cases of severe, widespread shingles 1
- Corticosteroids may shorten the degree and duration of acute zoster pain but have no essential effect on preventing postherpetic neuralgia 2
- Avoid prednisone in immunocompromised patients due to increased risk of disseminated infection 1
- Contraindications include poorly controlled diabetes, history of steroid-induced psychosis, severe osteoporosis, or prior severe steroid toxicity 1
Special Populations
Immunocompromised Patients
- Use IV acyclovir 10 mg/kg every 8 hours for disseminated or invasive disease 1
- Consider temporary reduction or discontinuation of immunosuppressive medications when clinically feasible 1
- Higher oral doses (acyclovir 400 mg orally 3–5 times daily) may be needed for uncomplicated disease 1
- Monitor closely for dissemination, visceral involvement, and treatment failure 1
Facial and 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 with urgency 1
- Elevation of the affected area promotes drainage of edema 1
- Keep skin well hydrated with emollients to avoid dryness and cracking 1
- Consider ophthalmology referral for suspected ocular involvement 4
Elderly Patients (≥50 Years)
- Systemic antiviral therapy is urgently indicated in all patients beyond age 50 due to higher risk of postherpetic neuralgia 2, 5
- Assess renal function before initiating therapy and adjust doses accordingly 1
- Monitor for acyclovir-related nephrotoxicity, especially with IV therapy 1
Renal Impairment
- Dose adjustments are mandatory to prevent acute renal failure 1
- For famciclovir: 500 mg every 8 hours for CrCl ≥60 mL/min, down to 250 mg every 24 hours for CrCl <20 mL/min 1
- Ensure adequate hydration during systemic acyclovir or valacyclovir therapy to reduce risk of crystalluria 1
Monitoring and Follow-Up
During Treatment
- Monitor renal function at initiation and once or twice weekly during IV acyclovir therapy 1
- Assess for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients receiving high-dose therapy 1
- Continue treatment until all lesions have completely scabbed 1
Recognizing Treatment Failure
- If lesions fail to begin resolving within 7–10 days, suspect acyclovir resistance 1
- Obtain viral culture with susceptibility testing 1
- For confirmed acyclovir-resistant VZV, switch to foscarnet 40 mg/kg IV every 8 hours until clinical resolution 1
- Acyclovir resistance is rare in immunocompetent patients (<0.5%) but occurs in up to 7% of immunocompromised patients 1
Infection Control
Contagiousness and Isolation
- Patients remain contagious until all lesions have fully crusted 1
- Avoid contact with susceptible individuals (those who have not had chickenpox or vaccination) until all lesions have crusted 1
- Cover lesions with clothing or dressings to minimize transmission risk 1
- For disseminated zoster (≥3 dermatomes), implement both airborne and contact precautions 1
- Healthcare workers with herpes zoster should be excluded from duty until all lesions dry and crust 1
Post-Exposure Prophylaxis
- Administer varicella-zoster immune globulin (VZIG) within 96 hours of exposure to high-risk individuals (pregnant women, immunocompromised patients, premature newborns) 1
- If VZIG is unavailable or >96 hours have passed, give a 7-day course of oral acyclovir beginning 7–10 days after exposure 1
Prevention: Vaccination
Recombinant Zoster Vaccine (Shingrix)
- Strongly recommended for all adults aged ≥50 years, regardless of prior herpes zoster episodes 1, 5, 6
- Provides >90% efficacy in preventing future herpes zoster episodes 1
- Administer after recovery from the current episode 1
- Ideally given before initiating immunosuppressive therapies (e.g., JAK inhibitors, B-cell depleting agents) 1
- For patients already on B-cell depleting therapy, give at least 4 weeks prior to the next scheduled dose to maximize immunogenicity 1
Common Pitfalls to Avoid
- Do not rely on topical antivirals—they are substantially less effective than systemic therapy 1
- Do not stop treatment at exactly 7 days if lesions have not fully scabbed 1
- Do not delay IV acyclovir in immunocompromised patients or those with severe disease 1
- Do not use corticosteroids in immunocompromised patients due to dissemination risk 1
- Do not forget renal dose adjustments—acyclovir can cause nephrotoxicity 1
- Do not overlook vaccination counseling—Shingrix should be offered after recovery 1