What is the optimal first‑line therapy for herpes zoster involving the V1 dermatome (forehead swelling) in a patient with no visual impairment?

Treatment of Herpes Zoster Involving the Forehead (V1 Dermatome) Without Visual Impairment

Initiate oral valacyclovir 1000 mg three times daily for 7 days immediately, ideally within 72 hours of rash onset, and arrange urgent ophthalmology evaluation within 24 hours even though vision is currently unaffected. 1, 2

Immediate Antiviral Therapy

Oral valacyclovir 1000 mg three times daily for 7 days is the first-line treatment for immunocompetent patients with herpes zoster involving the forehead. 1, 2 This regimen provides superior pain reduction compared to acyclovir and requires less frequent dosing (three times daily versus five times daily), which improves adherence. 3, 4

• Alternative oral options include famciclovir 500 mg three times daily for 7 days or acyclovir 800 mg five times daily for 7-10 days if valacyclovir is unavailable. 1, 5
• Treatment must be started within 72 hours of rash onset for optimal efficacy in reducing acute pain, accelerating lesion healing, and preventing postherpetic neuralgia, though some benefit may occur even when started later. 1, 3, 5
• Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period—this is the key clinical endpoint. 1

Critical Ophthalmology Referral

Urgent ophthalmology consultation is mandatory for any V1 (ophthalmic) distribution herpes zoster, regardless of current visual symptoms. 1 Forehead involvement places the patient at high risk for serious ocular complications including keratitis, uveitis, and secondary glaucoma that may develop days after initial presentation. 6

• The absence of current visual impairment does not exclude evolving ocular disease. 6
• Ophthalmology should evaluate for corneal involvement, intraocular inflammation, and elevated intraocular pressure. 6

Escalation to Intravenous Therapy

Switch to intravenous acyclovir 10 mg/kg every 8 hours if any of the following develop: 1

• Disseminated herpes zoster (≥3 dermatomes or visceral involvement)
• Signs of CNS involvement (altered mental status, severe headache, meningismus)
• Complicated ocular disease confirmed by ophthalmology
• Immunocompromised status (active chemotherapy, HIV, organ transplant, chronic immunosuppression)
• Failure to improve within 7-10 days on oral therapy

Symptomatic Management and Skin Care

• Apply cool compresses or ice packs to reduce pain and swelling during the acute vesicular phase. 1
• Keep the affected area elevated when possible to promote drainage of edema. 1
• Maintain skin hydration with emollients after lesions have crusted to prevent excessive dryness and cracking, but avoid applying products to active vesicles. 1
• Over-the-counter analgesics (acetaminophen or ibuprofen) provide relief for acute pain. 1
• Cover lesions with clothing or dressings to minimize transmission risk to susceptible individuals. 1

Pain Management

For acute neuropathic pain, initiate gabapentin titrated up to 2400 mg daily in divided doses as first-line therapy if over-the-counter analgesics are insufficient. 1 Gabapentin improves sleep quality but causes somnolence in approximately 80% of patients, so counsel accordingly. 1

• Pregabalin may be added for uncontrolled pain. 1
• Topical lidocaine provides minimal benefit during the acute phase and is not recommended as primary therapy. 1

Critical Monitoring Parameters

• Assess for new lesion formation daily—lesions should stop appearing within 4-6 days in immunocompetent hosts. 1
• Monitor for complete crusting of all lesions, which signals the end of the contagious period. 1
• If lesions fail to begin resolving within 7-10 days, suspect acyclovir resistance and obtain viral culture with susceptibility testing. 1
• Watch for signs of dissemination: fever, lesions in multiple dermatomes, respiratory symptoms, or neurological changes. 1

Renal Dosing Adjustments

For patients with creatinine clearance 30-49 mL/min, reduce valacyclovir to 1000 mg every 12 hours. 2 For creatinine clearance 10-29 mL/min, reduce to 1000 mg every 24 hours. 2 Ensure adequate hydration during therapy to minimize nephrotoxicity risk. 1

Common Pitfalls to Avoid

• Do not use topical antivirals—they are substantially less effective than systemic therapy and are not recommended. 1
• Do not apply topical corticosteroids to active shingles lesions, as they potentiate viral replication and increase risk of dissemination. 6, 1
• Do not delay ophthalmology referral even if the patient reports no visual symptoms—ocular complications can develop after initial presentation. 6, 1
• Do not stop antiviral therapy at exactly 7 days if lesions are still forming or have not completely scabbed. 1

Infection Control

• Patients are contagious until all lesions have crusted and should avoid contact with pregnant women, immunocompromised individuals, and anyone without prior varicella immunity or vaccination. 1
• Healthcare workers with active herpes zoster should be excluded from duty until all lesions are dry and crusted. 1

Prevention of Future Episodes

After recovery, strongly recommend the recombinant zoster vaccine (Shingrix) for all adults aged ≥50 years, regardless of this prior episode, to prevent future recurrences with >90% efficacy. 1, 5