What is the recommended treatment for a patient with shingles, considering antiviral therapy, pain management, and potential complications, especially in immunocompromised individuals?

Treatment of Shingles (Herpes Zoster)

For immunocompetent adults with uncomplicated shingles, initiate oral valacyclovir 1 gram three times daily or acyclovir 800 mg five times daily for 7 days, continuing until all lesions have completely scabbed; for immunocompromised patients or disseminated disease, use intravenous acyclovir 10 mg/kg every 8 hours. 1, 2

Antiviral Therapy: First-Line Treatment

Immunocompetent Patients

• Valacyclovir 1 gram orally three times daily for 7 days is the preferred first-line treatment due to superior bioavailability and less frequent dosing compared to acyclovir 1, 2, 3
• Alternative: Acyclovir 800 mg orally five times daily for 7-10 days 1, 2
• Alternative: Famciclovir 500 mg orally three times daily for 7 days 1, 4
• 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 ideally begins within 48 hours of rash onset for maximum benefit 1
• Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period—this is the key clinical endpoint 1

Immunocompromised Patients

• Intravenous acyclovir 10 mg/kg every 8 hours is mandatory for severely immunocompromised patients (HIV, active chemotherapy, organ transplant recipients) 1
• Continue IV therapy for minimum 7-10 days and until all lesions have completely scabbed 1
• Consider temporary reduction in immunosuppressive medications for disseminated or invasive disease 1
• For uncomplicated herpes zoster in kidney transplant recipients, oral acyclovir or valacyclovir may be used 1
• Monitor renal function closely during IV therapy with dose adjustments for renal impairment 1

Disseminated or Complicated Disease

• Intravenous acyclovir 10 mg/kg every 8 hours is required for disseminated herpes zoster (multi-dermatomal, visceral involvement) 1
• IV therapy is also indicated for CNS involvement, complicated ocular disease, or severe ophthalmic involvement 1
• Continue treatment at least until all lesions have scabbed 1

Pain Management

Acute Pain Control

• Valacyclovir significantly accelerates resolution of zoster-associated pain compared to acyclovir, with 23% superiority by day 29 3
• Famciclovir reduces median duration of postherpetic neuralgia by 3.5 months in patients ≥50 years compared to placebo 4
• For severe acute pain, consider narcotics for adequate pain control 5

Postherpetic Neuralgia Prevention and Treatment

• Early antiviral therapy (within 72 hours) reduces risk of postherpetic neuralgia 1, 5
• For established postherpetic neuralgia: tricyclic antidepressants or anticonvulsants in low dosages help control neuropathic pain 5
• Capsaicin cream, lidocaine patches, and nerve blocks can be used in selected patients 5
• Topical anesthetics provide minimal benefit and are not recommended as primary therapy 1

Corticosteroid Considerations

• Prednisone may be used as adjunctive therapy to antivirals in select cases of severe, widespread shingles 1
• Corticosteroids should generally be avoided in immunocompromised patients due to increased risk of disseminated infection 1
• Contraindications include poorly controlled diabetes, history of steroid-induced psychosis, severe osteoporosis, or prior severe steroid toxicity 1
• Benefits in pain reduction do not outweigh serious risks (infections, hypertension, myopathy, glaucoma, osteopenia) in most patients 1

Special Considerations by Location

Facial/Ophthalmic Involvement

• Facial zoster requires particular attention due to risk of cranial nerve complications 1
• Initiate oral valacyclovir 1 gram three times daily or famciclovir 500 mg three times daily within 72 hours, with particular urgency given risk of ophthalmic and cranial nerve complications 1
• Consider IV acyclovir for complicated facial zoster with suspected CNS involvement or severe ophthalmic disease 1
• Elevate affected area to promote drainage of edema 1
• Keep skin well hydrated with emollients to avoid dryness and cracking 1
• Ophthalmic involvement generally merits referral to ophthalmologist 5

Critical Treatment Pitfalls to Avoid

• Never use topical acyclovir—it is substantially less effective than systemic therapy 1, 2
• Do not discontinue antiviral therapy at exactly 7 days if lesions are still forming or have not completely scabbed 1
• Do not use acyclovir 400 mg three times daily for shingles—this dose is only appropriate for genital herpes or HSV suppression 1
• Starting treatment later than 72 hours after rash onset reduces efficacy, though some benefit may still occur 1
• Do not apply corticosteroid cream to active shingles rash—this can increase risk of severe disease and dissemination, especially in immunocompromised patients 1

Monitoring and Follow-Up

• Monitor for complete healing of lesions as the treatment endpoint 1
• Monitor renal function at initiation and once or twice weekly during IV acyclovir treatment 1
• Assess for thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients receiving high-dose therapy 1
• If lesions fail to begin resolving within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing 1
• For confirmed acyclovir resistance, switch to foscarnet 40 mg/kg IV every 8 hours until clinical resolution 1

Infection Control

• Patients should avoid contact with susceptible individuals until all lesions have crusted, as lesions are contagious to those who have not had chickenpox 1
• Varicella zoster immunoglobulin (or IVIG) within 96 hours of exposure is recommended for varicella-susceptible patients exposed to active infection 1
• If immunoglobulin unavailable or >96 hours have passed, give 7-day course of oral acyclovir beginning 7-10 days after exposure 1

Prevention

• The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes 1
• Vaccination should ideally occur before initiating immunosuppressive therapies 1
• The recombinant vaccine can be considered after recovery to prevent future episodes 1
• Live-attenuated vaccines (Zostavax) are contraindicated in immunocompromised patients 1