What is the recommended management of herpes zoster in adults, including antiviral therapy, pain control, steroid use, and vaccination?

Herpes Zoster Management

Antiviral Therapy

For uncomplicated herpes zoster in immunocompetent adults, initiate oral valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily within 72 hours of rash onset, continuing treatment until all lesions have completely scabbed. 1, 2

First-Line Oral Antivirals

• Valacyclovir 1000 mg three times daily for 7-10 days is preferred due to superior bioavailability and less frequent dosing compared to acyclovir, improving adherence and potentially reducing postherpetic neuralgia risk 2, 3
• Famciclovir 500 mg three times daily for 7 days offers equivalent efficacy with convenient dosing 2, 4
• Acyclovir 800 mg five times daily for 7-10 days remains effective but requires more frequent dosing 2, 5
• Treatment must begin within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia 2, 3
• Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period—this is the key clinical endpoint 2

Intravenous Therapy Indications

Switch to intravenous acyclovir 10 mg/kg every 8 hours for disseminated herpes zoster (≥3 dermatomes or visceral involvement), severely immunocompromised patients, CNS complications, or complicated ocular/facial disease. 2, 5

• Disseminated disease is defined by lesions in more than three dermatomes, visceral organ involvement (hepatitis, pneumonia, encephalitis), or hemorrhagic lesions 2
• Immunocompromised patients on active chemotherapy, high-dose corticosteroids (>40 mg prednisone daily), biologics, or with HIV should receive IV therapy 2
• Continue IV acyclovir for minimum 7-10 days and until all lesions have completely scabbed 2
• Monitor renal function at initiation and once or twice weekly during IV therapy, adjusting doses for renal impairment 2
• Watch for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients receiving high-dose IV acyclovir 2

Special Populations

• Immunocompromised patients may require extended treatment beyond 7-10 days as lesions develop over longer periods (7-14 days) and heal more slowly 2
• For kidney transplant recipients with uncomplicated herpes zoster, use oral acyclovir or valacyclovir 2
• Temporarily reduce or discontinue immunosuppressive medications in disseminated or invasive herpes zoster when clinically feasible, reintroducing only after all lesions have crusted 2

Treatment Failure and Resistance

• If lesions fail to begin resolving within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 2
• Acyclovir resistance is rare in immunocompetent patients but occurs in up to 7% of immunocompromised individuals 2
• For confirmed acyclovir-resistant VZV, switch to foscarnet 40 mg/kg IV every 8 hours until clinical resolution 2
• All acyclovir-resistant strains are also resistant to valacyclovir, and most resist famciclovir 2

Critical Pitfalls to Avoid

• Never use topical antivirals for shingles—they are substantially less effective than systemic therapy 2
• Do not use short-course antiviral regimens (1-3 days) designed for genital herpes; these are inadequate for VZV infection 2
• Maintain adequate hydration during systemic acyclovir or valacyclovir therapy to reduce crystalluria and nephrotoxicity risk 2

Pain Management

Acute Neuropathic Pain

Initiate gabapentin as first-line therapy for acute neuropathic pain, titrating in divided doses up to 2400 mg per day, while continuing over-the-counter analgesics for baseline pain control. 2

• Over-the-counter analgesics (acetaminophen, ibuprofen) provide initial pain relief 2
• Gabapentin improves sleep quality but causes somnolence in approximately 80% of patients—counsel patients about this common adverse effect 2
• Pregabalin may be added for uncontrolled pain, particularly in postherpetic neuralgia 2
• Tricyclic antidepressants (amitriptyline) can be used, but avoid combining multiple tricyclics—use gabapentin instead 2

Topical Therapies

• A single application of 8% capsaicin patch provides analgesia lasting at least 12 weeks for chronic peripheral neuropathic pain 2
• Apply 4% lidocaine preparation for 60 minutes before capsaicin to mitigate erythema and burning 2
• Topical ice or cold packs reduce pain and swelling during the acute phase 2

Adjunctive Pain Management

• Serotonin-norepinephrine reuptake inhibitors (SNRIs) can be considered as adjuncts based on efficacy in neuropathic pain 2
• Early initiation of anticonvulsants or tricyclic antidepressants in high-risk patients may prevent postherpetic neuralgia 4
• Epidural blocks and subcutaneous/intracutaneous injections of local anesthetics and steroids can be considered for high-risk patients 6

Corticosteroid Use

Corticosteroids are generally not recommended for routine herpes zoster management due to significant risks that outweigh potential benefits in most patients. 2

• Prednisone may be used as adjunctive therapy to antivirals only in select cases of severe, widespread shingles in immunocompetent patients 2
• Never use corticosteroids in immunocompromised patients with active shingles—this increases risk of severe disease and dissemination 2
• Corticosteroid use carries serious risks including increased infection susceptibility, hypertension, myopathy, glaucoma, aseptic necrosis, cataracts, Cushing syndrome, weight gain, and osteopenia 2
• Avoid corticosteroids in patients with poorly controlled diabetes, history of steroid-induced psychosis, severe osteoporosis, or prior severe steroid toxicity 2
• Do not apply topical corticosteroid cream to active shingles lesions—this can worsen infection and increase dissemination risk 2

Vaccination

Primary Vaccination Recommendations

All adults aged ≥50 years should receive the recombinant zoster vaccine (Shingrix) as a 2-dose series, with the second dose given 2-6 months after the first dose, regardless of prior herpes zoster history or previous Zostavax vaccination. 1

• Shingrix demonstrates 97.2% efficacy in preventing herpes zoster in adults aged ≥50 years 1
• Protection persists for at least 8 years with minimal waning, maintaining efficacy above 83.3% 1
• The minimum interval between doses is 4 weeks; if the second dose is delayed beyond 6 months, do not restart the series—simply administer the second dose 1
• There is no maximum allowable interval after the first dose—complete the series with a single second dose regardless of elapsed time 1

Vaccination After Herpes Zoster Episode

Administer Shingrix at least 2 months after complete clinical resolution of the acute herpes zoster episode to prevent future recurrences. 1, 6

• The 2-month interval allows complete symptom resolution and immune system recovery to optimize vaccine response 6
• The 10-year cumulative recurrence risk is 10.3%, supporting the need for post-zoster vaccination 1
• Having shingles once does not provide reliable protection against future episodes 1
• Complete both doses for optimal protection—do not stop after the first dose 1

Immunocompromised Patients

For immunocompromised adults aged ≥18 years, administer Shingrix on a shortened schedule with the second dose given 1-2 months after the first dose. 1

• Shingrix is safe for immunocompromised patients because it is a non-live recombinant vaccine 1
• Ideally complete the full 2-dose series before initiating highly immunosuppressive therapy (e.g., JAK inhibitors, rituximab, high-dose biologics) 1
• If urgent immunosuppressive therapy is required, administer at least the first dose before starting treatment 1
• Consider deferring vaccination until after holding immunosuppressive medication for an appropriate period before and 4 weeks after vaccination to ensure robust immune response 1

Patients Previously Vaccinated with Zostavax

Adults who previously received Zostavax should receive the full 2-dose Shingrix series at least 2 months after the last Zostavax dose. 1

• Zostavax efficacy declines to only 14.1% by year 10, providing inadequate long-term protection 1
• Shingrix offers significantly higher efficacy (>90%) compared to Zostavax across all age groups 1
• Do not use Zostavax for revaccination—only Shingrix is recommended 1

Critical Vaccination Pitfalls

• Never use live-attenuated Zostavax in immunocompromised patients—only Shingrix is appropriate due to risk of disseminated VZV infection from live vaccine 1, 6
• Do not order serologic testing before vaccination in adults ≥50 years—this delays protection and contradicts guideline recommendations 1
• Population studies show 88-91% of adults have VZV exposure despite lacking recalled chickenpox, making routine serologic testing unnecessary and cost-ineffective 1
• For truly VZV-seronegative patients (confirmed by testing), administer 2-dose varicella vaccine series spaced 4 weeks apart, not zoster vaccine 1

Timing with Other Vaccines

• Shingrix can be administered simultaneously or sequentially with inactivated influenza vaccines without required waiting periods 1
• Wait until acute flu symptoms (fever, severe malaise, myalgias) have resolved before receiving Shingrix 1
• There is no specific waiting period required after influenza illness before receiving Shingrix 1

Infection Control

Patients with herpes zoster must avoid contact with susceptible individuals (those without chickenpox history or vaccination) until all lesions have crusted, as lesions are contagious. 2

• Cover lesions with clothing or dressings to minimize transmission risk 2
• Healthcare workers with herpes zoster should be excluded from duty until all lesions dry and crust 2
• For localized herpes zoster (1-2 dermatomes), implement standard and contact precautions 2
• For disseminated zoster (≥3 dermatomes), implement both airborne and contact precautions 2
• Maintain physical separation of at least 6 feet from other patients in healthcare settings 2

Skin Care and Supportive Measures

• Keep skin well hydrated with emollients to avoid dryness and cracking, but avoid applying products to active vesicular lesions 2
• For facial zoster, elevate the affected area to promote drainage of edema and inflammatory substances 2
• Emollients may be used after lesions have crusted to prevent excessive dryness 2
• Monitor for complete healing of lesions as the treatment endpoint 2

Post-Exposure Prophylaxis

Administer varicella-zoster immune globulin (VZIG) within 96 hours of exposure to high-risk individuals including pregnant women, immunocompromised patients, and premature newborns <28 weeks gestation or <1,000 g. 2

• VZIG provides maximum benefit when administered as soon as possible after exposure 2
• If VZIG is unavailable or >96 hours have passed, give 7-day course of oral acyclovir beginning 7-10 days after varicella exposure 2
• Varicella vaccine administration within 3-5 days of exposure may modify disease if infection has not yet occurred 2