What is the recommended management for a patient with shingles who is at risk for complications?

Management of Complicated Shingles

For patients with complicated shingles (disseminated, multi-dermatomal, visceral involvement, or severe immunocompromise), intravenous acyclovir 10 mg/kg every 8 hours is the mandatory treatment, continuing for at least 7-10 days and until all lesions have completely scabbed. 1, 2

Initial Assessment and Risk Stratification

Complicated shingles requires immediate recognition of high-risk features:

• Disseminated disease: Lesions in more than 3 dermatomes, visceral organ involvement (hepatitis, pneumonia, encephalitis), or hemorrhagic lesions 3, 1
• Immunocompromised status: Active chemotherapy, HIV infection, chronic immunosuppressive therapy (thiopurines, biologics, high-dose corticosteroids >40 mg prednisone daily), or organ transplant recipients 3, 1
• Ophthalmic involvement: Trigeminal nerve distribution with risk of vision-threatening complications 1
• CNS complications: Encephalitis, meningitis, or Guillain-Barré syndrome 3, 4

Treatment Algorithm

Step 1: Initiate IV Acyclovir Immediately

• Dosing: Acyclovir 10 mg/kg IV every 8 hours (not 5 mg/kg, which is inadequate for severely immunocompromised hosts) 1, 2
• Duration: Minimum 7-10 days and continue until complete clinical resolution—meaning all lesions have crusted and no new lesions are forming 1, 2
• Hydration: Maintain adequate hydration to prevent acyclovir-induced nephrotoxicity 5

Step 2: Modify Immunosuppression

• Temporarily reduce or discontinue immunosuppressive medications in cases of disseminated or invasive herpes zoster if clinically feasible 3, 1, 2
• Immunosuppression can be reintroduced only after all vesicles have crusted over, fever has resolved, and the patient has been on antiviral therapy with clinical improvement 3, 1
• Do not commence or continue immunomodulator therapy during active chickenpox or herpes zoster infection 3

Step 3: Monitor for Complications

• Renal function: Check creatinine at initiation and monitor once or twice weekly during IV acyclovir therapy; adjust dosing for renal impairment 1, 5
• Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome: Assess in immunocompromised patients receiving high-dose therapy 1
• Visceral dissemination: Monitor for pneumonia, hepatitis (elevated transaminases), or CNS involvement 3, 1, 4
• Acyclovir resistance: If lesions fail to improve within 7-10 days despite treatment, obtain viral culture with susceptibility testing 1

Step 4: Transition to Oral Therapy

• Switch to oral therapy (valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily) once clinical improvement occurs and the patient can tolerate oral medications 1, 2
• Continue oral therapy until all lesions have completely scabbed 1, 2

Special Populations

Immunocompromised Patients on Active Chemotherapy

• Mandatory IV acyclovir due to high risk of dissemination and vision-threatening complications, particularly with agents like daratumumab, bortezomib, melphalan, and prednisone 1
• Consider prophylactic acyclovir 400 mg daily for patients receiving proteasome inhibitor-based therapies to prevent future episodes 1

Pregnant Women

• Varicella-zoster immune globulin (VZIG) within 96 hours of exposure for VZV-susceptible pregnant women 1, 2
• If VZIG unavailable or >96 hours have passed, initiate a 7-day course of oral acyclovir beginning 7-10 days after exposure 1, 2

HIV-Infected Patients

• Higher oral doses may be needed (acyclovir 800 mg 5-6 times daily or valacyclovir 1 gram three times daily) for uncomplicated cases 1
• Consider long-term acyclovir prophylaxis (400 mg 2-3 times daily) for patients with frequent recurrences 1

Management of Acyclovir-Resistant Cases

• Foscarnet 40 mg/kg IV every 8 hours until clinical resolution for proven or suspected acyclovir-resistant herpes zoster 1, 2
• All acyclovir-resistant strains are also resistant to valacyclovir, and most are resistant to famciclovir 1
• Foscarnet requires close monitoring of renal function and electrolytes (hypocalcemia, hypophosphatemia, hypomagnesemia, hypokalemia) 2

Infection Control Measures

• Implement airborne and contact precautions for disseminated zoster (lesions in >3 dermatomes) or immunocompromised patients 1
• Patients should avoid contact with susceptible individuals (pregnant women, immunocompromised persons, those without varicella immunity) until all lesions have crusted 1, 2
• Cover lesions with clothing or dressings to minimize transmission risk 1
• Healthcare workers with herpes zoster should be excluded from duty until all lesions dry and crust 1

Common Pitfalls to Avoid

• Do not use oral antivirals for complicated or disseminated shingles—IV therapy is mandatory 1, 2
• Do not discontinue treatment at exactly 7 days if lesions are still forming or have not completely scabbed; treatment duration is determined by lesion healing status, not calendar days 1, 2
• Do not use topical antivirals—they are substantially less effective than systemic therapy 1, 2
• Do not use corticosteroids in immunocompromised patients with active shingles due to increased risk of disseminated infection 1
• Do not delay treatment waiting for laboratory confirmation in immunocompromised patients with typical clinical presentation 1

Post-Recovery Prevention

• Recombinant zoster vaccine (Shingrix) is strongly recommended for all adults aged 50 years and older after recovery from the current episode, regardless of prior herpes zoster episodes 1, 2
• Vaccination provides >90% efficacy in preventing future recurrences 1
• Ideally administer before initiating immunosuppressive therapies, but the recombinant vaccine (unlike live-attenuated Zostavax) is under investigation for use in immunocompromised patients 1