What is the management of a patient presenting with symptoms of shingles, including a painful rash, blistering, and itching?

Management of Shingles (Herpes Zoster)

For patients presenting with symptoms of shingles—including painful rash, blistering, and itching—initiate oral antiviral therapy immediately, ideally within 72 hours of rash onset, with valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily for 7-10 days, continuing treatment until all lesions have completely scabbed. 1, 2, 3

Initial Symptom Recognition

Patients typically experience prodromal symptoms before the visible rash appears 4:

• Burning pain, itching, and/or paresthesias that precede the rash by several days 4
• Constitutional symptoms including fever, headache, malaise, and anorexia in some cases 4
• Dermatomal distribution of pain and subsequent rash following reactivation of latent varicella-zoster virus from dorsal root ganglia 5

First-Line Antiviral Treatment

Standard Dosing Regimens for Immunocompetent Adults

Valacyclovir (preferred for convenience):

• 1 gram orally three times daily for 7 days 2
• Superior bioavailability compared to acyclovir, requiring less frequent dosing 1, 6
• Treatment should continue until all lesions have completely scabbed, not just for an arbitrary 7-day period 1

Famciclovir (equally effective alternative):

• 500 mg orally three times daily for 7 days 3
• Comparable efficacy to valacyclovir for acute lesion healing and postherpetic neuralgia prevention 1, 6
• Longer intracellular half-life than acyclovir allows for less frequent dosing 7

Acyclovir (effective but requires more frequent dosing):

• 800 mg orally five times daily for 7-10 days 1
• Requires more frequent administration due to lower bioavailability 6

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. However, treatment initiated beyond 72 hours may still provide benefit, particularly for pain reduction 6. The key is to start as soon as possible after symptom recognition. 1, 2, 3

When to Escalate to Intravenous Therapy

Intravenous acyclovir 10 mg/kg every 8 hours is mandatory for: 1

• Disseminated or invasive herpes zoster (multi-dermatomal involvement, visceral involvement) 1
• Immunocompromised patients, including those on chemotherapy or with HIV infection 1
• Complicated facial zoster with suspected CNS involvement 1
• Severe ophthalmic disease 1

Continue IV therapy for a minimum of 7-10 days and until all lesions have completely scabbed. 1

Special Population Considerations

Immunocompromised Patients

For severely immunocompromised hosts (HIV, cancer, transplant recipients): 1

• Start with intravenous acyclovir 10 mg/kg every 8 hours rather than oral therapy 1
• Consider temporary reduction in immunosuppressive medications for disseminated disease 1
• Monitor closely for dissemination, as cutaneous dissemination occurs in 25-50% of HIV-infected patients 4
• Treatment duration may need to extend well beyond 7-10 days, as lesions develop over longer periods (7-14 days) and heal more slowly 1

Renal Impairment

Dose adjustments are mandatory to prevent acute renal failure: 1, 2, 3

Valacyclovir dosing adjustments: 2

• CrCl 30-49 mL/min: 1 gram every 12 hours
• CrCl 10-29 mL/min: 1 gram every 24 hours
• CrCl <10 mL/min: 500 mg every 24 hours

Famciclovir dosing adjustments for herpes zoster: 3

• CrCl ≥60 mL/min: 500 mg every 8 hours
• CrCl 40-59 mL/min: 500 mg every 12 hours
• CrCl 20-39 mL/min: 500 mg every 24 hours
• CrCl <20 mL/min: 250 mg every 24 hours

Monitor renal function at initiation and once or twice weekly during IV acyclovir therapy. 1

Symptomatic Management

Pain Control

For acute zoster pain: 5

• Oral analgesics including NSAIDs for mild-to-moderate pain 5
• Narcotics may be required for severe acute pain 5
• Topical anesthetics provide minimal benefit and are not recommended as primary therapy 1

For neuropathic pain components: 5

• Tricyclic antidepressants in low dosages 5
• Anticonvulsants (gabapentin, pregabalin) 5
• Lidocaine patches for localized pain 5

Skin Care

• Keep the affected area clean and dry 1
• Avoid applying products to active vesicular lesions 1
• Emollients may be used after lesions have crusted to prevent excessive dryness 1
• Elevation of affected facial areas to promote drainage of edema 1

Critical Pitfalls to Avoid

Do NOT use topical antivirals—they are substantially less effective than systemic therapy and are not recommended. 1

Do NOT routinely add corticosteroids: 1

• While prednisone may provide modest benefits in select cases of severe, widespread disease, the risks (infections, hypertension, myopathy, glaucoma, osteopenia) generally outweigh benefits 1
• Corticosteroids are contraindicated in immunocompromised patients due to increased risk of disseminated infection 1

Do NOT discontinue antiviral therapy at exactly 7 days if lesions are still forming or have not completely scabbed—treatment must continue until complete scabbing occurs 1.

Infection Control

Patients with active shingles should avoid contact with susceptible individuals (those who have not had chickenpox or vaccination) until all lesions have crusted, as lesions are contagious and can transmit varicella 1.

Prevention of Postherpetic Neuralgia

Early antiviral treatment within 72 hours significantly reduces the risk of postherpetic neuralgia (PHN) by shortening viral shedding, accelerating healing, and lessening acute pain intensity 4. Famciclovir recipients experience approximately twofold faster resolution of PHN compared to placebo, with median duration reduced by approximately 2-3 months 8, 9. Valacyclovir alleviates zoster-associated pain and postherpetic neuralgia significantly faster than acyclovir 6.

Vaccination for Future Prevention

The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes, to prevent future recurrences 1. Vaccination should ideally occur before initiating immunosuppressive therapies 1.

Monitoring for Treatment Failure

If lesions fail to begin resolving within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 1. For confirmed acyclovir-resistant herpes zoster, switch to foscarnet 40 mg/kg IV every 8 hours until clinical resolution 1.