What are the guidelines for managing disseminated zoster (shingles)?

Management of Disseminated Zoster

Intravenous acyclovir at a dose of 1500 mg per square meter of body surface area per day (approximately 10 mg/kg every 8 hours) is the recommended first-line treatment for disseminated herpes zoster in immunocompromised patients. 1

Definition and Clinical Presentation

Disseminated zoster is defined as:

• More than 20 vesicular lesions outside the primary or adjacent dermatomes
• Systemic involvement of visceral organs (e.g., lungs, liver, brain)
• Usually occurs in immunocompromised patients

Treatment Algorithm

First-Line Therapy

• Immunocompromised patients with disseminated zoster:
  • Intravenous acyclovir: 10 mg/kg every 8 hours (1500 mg/m²/day) 1
  • Duration: Minimum 7 days or until all lesions have crusted over
  • Continue therapy until resolution of cutaneous or visceral disease is complete

Alternative Therapies

• If acyclovir resistance is suspected (indicated by "stitch-like appearance" on vesicles or poor clinical response after 72 hours):

  • Add intravenous vidarabine 10 mg/kg/day as combination therapy 2
  • OR switch to foscarnet or cidofovir for acyclovir-resistant cases 3, 4

• For immunocompromised patients with less severe disease:

  • Oral valacyclovir 1 g three times daily for 7 days 5
  • OR oral famciclovir 500 mg three times daily for 7 days 4

Transitioning from IV to Oral Therapy

• Consider transition to oral therapy once clinical improvement occurs 4
• Options include:
  • Valacyclovir 1 g three times daily
  • Famciclovir 500 mg three times daily
  • Acyclovir 800 mg five times daily

Management of Complications

Ocular Involvement

• Immediate ophthalmology consultation for any patient with eye involvement 4
• Topical corticosteroids may be beneficial for inflammatory complications but should be used with caution and only in conjunction with systemic antiviral therapy 4
• Topical antibiotics may be needed to prevent secondary bacterial infection of vesicles 4

Pain Management

• Acute pain:

  • Mild: NSAIDs or acetaminophen
  • Moderate to severe: Gabapentin, pregabalin, or tricyclic antidepressants
  • Severe refractory pain: Short-term opioids as last resort 4

• Postherpetic neuralgia:

  • First-line: Gabapentin, pregabalin, nortriptyline, desipramine, duloxetine, venlafaxine, or topical lidocaine 4
  • Start tricyclic antidepressants at lower doses and titrate slowly to minimize anticholinergic side effects 4
  • Obtain ECG before starting TCAs in patients over 40 years 4

Special Populations

HIV-Infected Patients

• Higher doses and longer duration of antiviral therapy may be required 3
• Consider prophylaxis against recurrent episodes in patients with frequent or severe recurrences using daily suppressive therapy with oral acyclovir or famciclovir 3

Pregnant Women

• Varicella zoster immune globulin (VZIG) is recommended for VZV-susceptible pregnant women within 96 hours after exposure to VZV 3
• If oral acyclovir is used, VZV serology should be performed so that the drug can be discontinued if the patient is seropositive for VZV 3

Follow-up and Monitoring

• Regular monitoring of patients on antiviral therapy for potential adverse effects
• Follow-up within 1-2 weeks to assess:
  • Resolution of cutaneous lesions
  • Persistence of pain
  • Development of complications
• Extended follow-up for patients at high risk of postherpetic neuralgia 4

Prevention

• No preventive measures are currently available specifically for shingles in immunocompromised patients 3
• No drug has been proven to prevent the recurrence of shingles in HIV-infected persons 3
• Household contacts (especially children) of susceptible immunocompromised persons should be vaccinated against VZV if they have no history of chickenpox and are seronegative for HIV 3

Clinical Pearls

• Early initiation of antiviral therapy (within 72 hours of rash onset) is associated with better outcomes and fewer complications 1
• Disseminated zoster should be treated aggressively in immunocompromised patients to prevent visceral dissemination
• Monitor renal function during intravenous acyclovir therapy and adjust dosing accordingly