What is the recommended treatment for oral herpes simplex?

Treatment of Oral Herpes Simplex

For oral herpes simplex (cold sores), the recommended first-line treatment is oral antiviral therapy with valacyclovir 2g twice daily for 1 day, which reduces healing time and symptom duration. 1

First-Line Treatment Options

Episodic Treatment

• Valacyclovir: 2g twice daily for 1 day (preferred due to convenience and efficacy) 1
• Acyclovir: 400mg orally three times daily for 5-7 days OR 200mg orally five times daily for 5-7 days 1, 2
• Famciclovir: Single dose of 1500mg (reduces median healing time by 1.8 days) 1

For Severe Cases

• Acyclovir: 400mg five times daily for 7-10 days 1
• Intravenous acyclovir: 5-10 mg/kg three times daily until lesions begin to regress, then switch to oral therapy (for severe cases) 1

Treatment Considerations

Timing of Treatment

• Treatment should be initiated at the first sign of prodrome (tingling, burning sensation) for maximum efficacy 1
• Delayed treatment (>48 hours after symptom onset) significantly decreases efficacy 1
• Antivirals typically decrease episode duration by approximately one day but don't completely abort lesions 1, 3

Special Populations

• Immunocompromised patients: Higher doses and longer treatment duration are recommended
  • Acyclovir 400mg five times daily for 7-10 days 1, 2
  • For severe cases resistant to standard therapy, foscarnet 40mg/kg IV three times daily may be necessary 2, 4

Topical Options

• Orolabial lesions: Can be treated with topical agents, though less effective than oral therapy 2, 3
  • Ganciclovir 0.15% gel three to five times per day 2
  • Acyclovir 5% cream (may reduce duration if applied early) 3

Prevention of Recurrences

Suppressive Therapy

For patients with frequent recurrences (≥6 episodes per year):

• Acyclovir: 400mg twice daily 1, 3
• Valacyclovir: 500-2000mg daily 1, 3

Preventive Measures

• Use sunscreen (SPF 15 or above) to prevent UV-triggered recurrences 1, 3
• Avoid known triggers: fever, psychological stress, and local trauma 1
• Keep the area clean and dry to prevent secondary infection 1

Management of Treatment Failure

If lesions do not begin to resolve within 7-10 days:

1. Consider antiviral resistance (rare in immunocompetent patients, <0.5%) 1
2. For suspected acyclovir-resistant HSV:
   • Obtain viral culture and susceptibility testing 2
   • Consider foscarnet 40mg/kg IV three times daily or 60mg/kg IV twice daily 2, 4
   • For accessible lesions, topical trifluridine may be used 2, 4

Side Effects and Monitoring

Common side effects of oral antivirals include:

• Acyclovir: Nausea/vomiting (2.7%), headache, diarrhea 5
• Famciclovir: Headache (<10%), nausea (<4%) 6

No routine laboratory monitoring is needed for most patients unless they have significant renal impairment 2.

Caveats and Pitfalls

• Topical corticosteroids should be avoided as they can potentiate HSV infection 2
• Treatment is most effective when started within 48 hours of symptom onset 1
• Patients should be advised that antivirals reduce but do not eliminate viral shedding; transmission can still occur during asymptomatic periods 2
• Resistance to antivirals remains low in immunocompetent patients but may develop in immunocompromised individuals 1, 4