What is the recommended treatment for a patient with a normal immune system and no contraindications experiencing a herpes simplex or herpes zoster breakout?

Treatment of Herpes Breakout

For immunocompetent patients with herpes simplex, use oral acyclovir 200 mg five times daily for 7-10 days for initial episodes, or 200-800 mg orally for 5 days for recurrent episodes; for herpes zoster, use valacyclovir 1 gram three times daily for 7 days or acyclovir 800 mg five times daily for 7-10 days, initiated within 72 hours of rash onset. 1, 2, 3, 4, 5

Herpes Simplex Treatment Algorithm

First Clinical Episode (Genital or Orolabial)

• Acyclovir 200 mg orally 5 times daily for 7-10 days until clinical resolution 1
• For herpes proctitis specifically: Acyclovir 400 mg orally 5 times daily for 10 days 1
• Therapy is most effective when started within 48 hours of symptom onset 1, 4

Recurrent Episodes

• Acyclovir 200 mg orally 5 times daily for 5 days, OR 1
• Acyclovir 400 mg orally 3 times daily for 5 days, OR 1
• Acyclovir 800 mg orally 2 times daily for 5 days 1
• Treatment provides limited benefit unless initiated during prodrome or within 2 days of lesion onset 1
• Most immunocompetent patients with recurrent disease do not benefit significantly from treatment 1

Cold Sores (Herpes Labialis)

• Valacyclovir 2 grams twice daily for 1 day (12 hours apart) 4
• Initiate at earliest symptom (tingling, itching, burning) 4

Suppressive Therapy (for frequent recurrences ≥6 per year)

• Acyclovir 400 mg orally twice daily 1
• Alternative: Acyclovir 200 mg orally 3-5 times daily 1
• Reduces recurrence frequency by at least 75% 1
• After 1 year of continuous therapy, discontinue to reassess recurrence rate 1

Herpes Zoster (Shingles) Treatment Algorithm

Uncomplicated Herpes Zoster

• First-line: Valacyclovir 1 gram orally three times daily for 7 days 2, 3, 4
• Alternative: Acyclovir 800 mg orally 5 times daily for 7-10 days 1, 2, 3, 5
• Alternative: Famciclovir 500 mg orally three times daily for 7 days 2, 3
• Critical timing: Initiate within 72 hours of rash onset for optimal efficacy in reducing acute pain and preventing postherpetic neuralgia 2, 3, 4
• Treatment is most effective when started within 48 hours 2, 5
• Continue treatment until all lesions have completely scabbed, not just for an arbitrary 7-day period 2, 3

Disseminated or Invasive Herpes Zoster

• Intravenous acyclovir 5-10 mg/kg every 8 hours 2, 3
• Continue for minimum 7-10 days and until clinical resolution 2, 3
• Consider temporary reduction in immunosuppressive medications if applicable 2, 3
• Switch to oral therapy once clinical improvement occurs 3

Critical Treatment Considerations

Topical Therapy

Topical acyclovir is substantially less effective than oral therapy and its use is discouraged for both herpes simplex and herpes zoster 1, 2

Severe Disease Requiring Hospitalization

• Intravenous acyclovir 5-10 mg/kg every 8 hours for 5-7 days until clinical resolution 1
• Indications: disseminated infection, encephalitis, pneumonitis, hepatitis, multi-dermatomal involvement, CNS complications, or complicated ocular disease 1, 2, 3

Acyclovir-Resistant Cases

• Foscarnet 40 mg/kg IV every 8 hours until clinical resolution 2, 3, 6
• Resistance is extremely rare in immunocompetent patients but occurs more frequently in immunocompromised patients on prolonged suppressive therapy 1, 2
• All acyclovir-resistant strains are also resistant to valacyclovir, and most to famciclovir 2
• Topical cidofovir gel 1% applied once daily for 5 consecutive days may be an alternative 2

Common Pitfalls and Caveats

Timing Errors

• Do not delay treatment beyond 72 hours for herpes zoster—efficacy decreases significantly 2, 3, 4
• For herpes simplex recurrences, treatment after 2 days of lesion onset provides minimal benefit 1

Duration Errors

• Do not stop treatment at exactly 7 days if lesions are still forming or have not completely scabbed—continue until all lesions have crusted 2, 3
• Immunocompromised patients may require extended treatment beyond 7-10 days as lesions develop over longer periods (7-14 days) and heal more slowly 2

Dosing Errors

• Do not use genital herpes dosing (400 mg TDS) for herpes zoster—this is inadequate for VZV infection 2
• Herpes zoster requires higher doses: acyclovir 800 mg five times daily or valacyclovir 1 gram three times daily 2, 3, 4

Renal Function Monitoring

• Monitor renal function closely during IV acyclovir therapy with dose adjustments for renal impairment 2, 4, 5
• Valacyclovir and famciclovir require dose adjustments in renal impairment 2, 3

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 or vaccination 2
• Advise abstaining from sexual activity while herpes simplex lesions are present 1

Post-Treatment Prevention

• Recombinant zoster vaccine (Shingrix) is recommended for all adults ≥50 years, regardless of prior herpes zoster episodes, to prevent future recurrences 2, 3
• Vaccination should ideally occur before initiating immunosuppressive therapies 2