What is the treatment for herpes labialis?

Treatment of Herpes Labialis (Cold Sores)

For herpes labialis (cold sores), the recommended first-line treatment is valacyclovir 2g twice daily for 1 day, which offers convenience and efficacy with strong evidence support. 1

Antiviral Treatment Options

First-Line Options:

• Valacyclovir: 2g twice daily for 1 day
  • Recommended by the American Academy of Dermatology (AAD)
  • Convenient dosing schedule with proven efficacy
  • Evidence level I (highest quality evidence)

Alternative Regimens:

• Famciclovir: 1500mg as a single dose

  • Reduces median time to healing by 1.8 days compared to placebo
  • Generally mild adverse events
  • FDA-approved for herpes labialis 2
  • In clinical trials, famciclovir 1500mg single dose showed median healing time of 4.4 days vs 6.2 days with placebo 2

• Acyclovir: Two options

  • 200mg orally five times daily for 5-7 days, OR
  • 400mg orally three times daily for 5-7 days
  • CDC-recommended with evidence level I

Timing of Treatment

Treatment should be initiated at the first sign or symptom of herpes labialis (e.g., tingling, itching, burning, pain, or lesion) 1, 2. The efficacy of treatment significantly decreases when started later in the course of the outbreak.

Special Populations

Immunocompromised Patients:

• Higher doses of acyclovir (400mg five times daily)
• Longer treatment duration (7-10 days)
• Consider IV acyclovir in severe cases
• Evidence level III 1

Pregnant Patients:

• Acyclovir 400mg orally three times daily for 5-7 days OR
• Acyclovir 200mg orally five times daily for 5-7 days
• Established safety profile in pregnancy
• Evidence level I 1

Supportive Care

• Pain Management: Topical anesthetics may be considered during the vesicular phase
• Hygiene: Keep the area clean and dry to prevent secondary infection
• Prevention:
  • Use sunscreen (SPF 15 or above) to prevent UV-triggered recurrences
  • Avoid known triggers (UV radiation, fever, psychological stress, local trauma)
  • Evidence level II 1

Treatment Failure

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

• Consider treatment failure and possible resistance
• Alternative treatments may include topical trifluridine or intravenous foscarnet (40mg/kg three times daily)
• Evidence level II 1

Monitoring

No routine laboratory monitoring is needed for most patients unless they have significant renal impairment (evidence level III) 1.

Important Considerations

• Resistance to antivirals remains low (<0.5%) in immunocompetent patients 1
• Common side effects of oral antivirals include nausea/vomiting, headache, and diarrhea
• Treatment typically reduces healing time by approximately one day but does not completely abort lesion development 3
• Early treatment (within 1 hour of symptom onset) shows better outcomes 4

While older studies suggested limited benefit of treatment for recurrent orolabial herpes 5, more recent guidelines and clinical trials support the use of antiviral therapy, particularly with the newer agents like valacyclovir and famciclovir that offer improved bioavailability and convenient dosing schedules.