What is the recommended treatment for a patient presenting with Herpes zoster?

Treatment of Herpes Zoster

For uncomplicated herpes zoster, initiate oral valacyclovir 1 gram three times daily for 7 days, starting within 72 hours of rash onset, and continue treatment until all lesions have completely scabbed. 1, 2, 3

Treatment Algorithm Based on Disease Severity and Patient Status

Immunocompetent Patients with Uncomplicated Herpes Zoster

First-line therapy:

• Valacyclovir 1 gram orally three times daily for 7 days 1, 2, 3, 4
• Alternative: Acyclovir 800 mg orally five times daily for 7-10 days 1, 2, 5
• Alternative: Famciclovir 500 mg orally three times daily for 7 days 1

Critical timing considerations:

• 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, 2
• Treatment is most effective when started within 48 hours 5, 3
• Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period 1, 2

Valacyclovir advantages over acyclovir:

• Superior bioavailability (3-5 fold higher) allowing less frequent dosing 6, 4, 7
• Significantly accelerates resolution of herpes zoster-associated pain compared to acyclovir (median 38 days vs 51 days) 4
• Reduces duration of postherpetic neuralgia and decreases proportion of patients with pain persisting at 6 months (19.3% vs 25.7%) 4
• Similar safety profile to acyclovir 6, 4, 7

Immunocompromised Patients

For uncomplicated herpes zoster in immunocompromised patients:

• Oral valacyclovir 1 gram three times daily 1, 8
• Higher doses (valacyclovir 2 grams three times daily) reach plasma levels similar to IV acyclovir but showed no additional benefit over standard dosing in clinical trials 8
• Monitor closely for dissemination and visceral complications 2, 9

For disseminated or invasive herpes zoster:

• Intravenous acyclovir 10 mg/kg every 8 hours 1, 2, 10
• Continue for minimum 7-10 days and until complete clinical resolution (all lesions scabbed) 1, 2, 10
• Temporarily reduce immunosuppressive medications if applicable 1, 2
• Switch to oral therapy once clinical improvement occurs 2
• Monitor renal function daily with dose adjustments for renal insufficiency 10

Indications for IV therapy:

• Disseminated herpes zoster (multi-dermatomal involvement, visceral involvement) 1, 2
• CNS complications (encephalitis, meningitis) 10
• Complicated ophthalmic disease 1
• Severe immunocompromise with active chemotherapy 1

Special Populations and Situations

Facial/ophthalmic herpes zoster:

• Requires urgent treatment due to risk of vision-threatening complications and cranial nerve involvement 1
• Valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily 1
• Elevation of affected area to promote drainage of edema 1
• Keep skin well hydrated with emollients 1

Renal impairment:

• Mandatory dose adjustments to prevent acute renal failure 1, 5, 3
• For valacyclovir with CrCl 30-49 mL/min: reduce frequency 3
• For valacyclovir with CrCl 10-29 mL/min: further dose reduction required 3
• Monitor renal function closely during IV acyclovir therapy 1

Acyclovir-resistant cases:

• Foscarnet 40 mg/kg IV every 8 hours until clinical resolution 1, 2
• All acyclovir-resistant strains are also resistant to valacyclovir and most to famciclovir 1
• Suspect resistance if lesions fail to resolve within 7-10 days despite treatment 1

Common Pitfalls and Caveats

Do not stop treatment prematurely:

• The key clinical endpoint is complete scabbing of all lesions, not calendar days 1, 2
• Immunocompromised patients may develop new lesions for 7-14 days and require extended treatment 1

Avoid ineffective therapies:

• Topical antivirals are substantially less effective than systemic therapy and are not recommended 11, 1, 2
• Topical anesthetics provide minimal benefit and are not recommended as primary therapy 1

Do not use corticosteroids inappropriately:

• Corticosteroids should generally be avoided in immunocompromised patients due to increased risk of disseminated infection 1
• Prednisone carries significant risks (infections, hypertension, myopathy, glaucoma, osteopenia) that outweigh benefits in most patients 1

Infection control:

• Patients remain contagious until all lesions have crusted 1
• Avoid contact with susceptible individuals (non-immunized pregnant women, immunocompromised individuals, newborns) 1, 10

Post-Exposure Prophylaxis

For varicella-susceptible patients exposed to active varicella zoster:

• Varicella zoster immunoglobulin (VZIG) within 96 hours of exposure 1, 2
• If VZIG unavailable or >96 hours have passed: oral acyclovir for 7 days beginning 7-10 days after exposure 1, 2

Prevention

Vaccination:

• Recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes 1, 2
• Vaccination should ideally occur before initiating immunosuppressive therapies 1
• Live-attenuated vaccine (Zostavax) is contraindicated in immunocompromised patients 1