Intravenous Acyclovir is the Most Appropriate Next Step
This immunocompromised patient with multiple myeloma on active chemotherapy presenting with herpes zoster ophthalmicus (HZO) requires immediate intravenous acyclovir 10 mg/kg every 8 hours. 1, 2
Clinical Reasoning
Why IV Acyclovir Over Oral Valacyclovir
This patient has multiple high-risk features that mandate intravenous therapy rather than oral treatment:
- Active immunosuppression from multiple myeloma and chemotherapy (daratumumab, bortezomib, melphalan, prednisone) places him at extremely high risk for disseminated disease 2, 3
- Ophthalmic involvement (right eyelid erythema, crusting, discharge, and blurred vision) represents vision-threatening disease requiring aggressive treatment 1, 2
- Vesicular rash extending from forehead to nose indicates V1 dermatome involvement, which carries 50-70% risk of ocular complications 1
The FDA label explicitly indicates intravenous acyclovir for "varicella-zoster (shingles) infections in immunocompromised patients," and clinical trials demonstrated superiority in reducing cutaneous and visceral dissemination in this population 3. Immunocompromised patients with herpes zoster require high-dose intravenous acyclovir (10 mg/kg every 8 hours) as the treatment of choice, particularly with multi-dermatomal involvement or ophthalmic disease. 2
Why Not the Other Options
Option A (Oral valacyclovir): Reserved only for uncomplicated, localized herpes zoster in immunocompromised patients without ocular involvement 1, 4. This patient's ophthalmic involvement and severe immunosuppression from active chemotherapy disqualify oral therapy 2
Option C (Vancomycin and cefepime): While secondary bacterial infection is possible given the yellow crusting, the primary pathology is clearly varicella-zoster virus based on the characteristic dermatomal vesicular rash and temporal progression 1. Delaying antiviral therapy to treat presumed bacterial infection would be inappropriate and potentially vision-threatening 2
Option D (Ophthalmic corticosteroids): Absolutely contraindicated in acute herpes zoster ophthalmicus until antiviral therapy is established, as corticosteroids can potentiate viral replication and worsen infection 5, 1. Topical corticosteroids may be considered later for stromal inflammation, but only after adequate antiviral coverage 5
Treatment Protocol
Immediate Management
- Start IV acyclovir 10 mg/kg every 8 hours immediately without waiting for confirmatory testing 2, 3
- Continue treatment for minimum 7-10 days and until all lesions have completely scabbed (not just an arbitrary 7-day course) 1, 2
- Consider temporary reduction or holding of immunosuppressive medications (particularly bortezomib and prednisone) in consultation with oncology, as disseminated VZV infection may require this intervention 1, 4, 2
Monitoring Requirements
- Monitor renal function closely with dose adjustments for creatinine clearance, as acyclovir is nephrotoxic and renally cleared 2, 3
- Assess for cessation of new lesion formation within 48-72 hours of starting therapy 2
- Watch for visceral dissemination (hepatitis, pneumonitis, encephalitis) which would require extended IV therapy 2
Ophthalmology Consultation
Urgent ophthalmology evaluation is mandatory given the ocular involvement, blurred vision, and eyelid findings 1. The ophthalmologist will assess for:
- Corneal involvement (dendritic ulcers, stromal keratitis)
- Anterior uveitis
- Elevated intraocular pressure
- Retinal involvement
Transition to Oral Therapy
Switch to oral valacyclovir 1000 mg three times daily only after clinical improvement occurs (afebrile, no new lesions for 24 hours, no visceral involvement) to complete the full treatment course 4, 6. Total duration of therapy (IV plus oral) should continue until complete resolution of lesions 4, 2.
Critical Pitfalls to Avoid
- Do not use oral antivirals as initial therapy in severely immunocompromised patients with ophthalmic involvement - this represents inadequate treatment and risks permanent vision loss 1, 2
- Do not apply topical corticosteroids before establishing antiviral therapy - this can cause devastating progression of infection 5
- Do not discontinue therapy at exactly 7 days if lesions are still active - treatment must continue until all lesions have scabbed 1, 2
- Do not forget to monitor for acyclovir resistance if lesions fail to improve within 7-10 days, requiring switch to foscarnet 40 mg/kg IV every 8 hours 2, 7
Long-term Prophylaxis
After acute treatment, consider long-term acyclovir prophylaxis (400-800 mg twice daily) while on proteasome inhibitor therapy (bortezomib), as this population has high rates of VZV reactivation 1, 2.