What treatment options are available for fever blisters?

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Last updated: October 10, 2025View editorial policy

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Treatment Options for Fever Blisters (Cold Sores)

For fever blisters (cold sores), oral antiviral medications like famciclovir (1500 mg single dose) or valaciclovir (2g twice daily for 1 day) are the most effective treatments, while topical docosanol 10% cream is a reasonable over-the-counter option for milder cases. 1

Understanding Fever Blisters

  • Fever blisters, also known as cold sores or herpes labialis, are primarily caused by herpes simplex virus type 1 (HSV-1) 1
  • These recurrent episodes can be frequent, painful, long-lasting, and disfiguring for affected individuals 1
  • The goal of treatment is to block viral replication to shorten symptom duration and accelerate healing of lesions 1

Treatment Options

Oral Antiviral Medications

  • Oral antivirals have proven highly efficacious in treating herpes labialis based on placebo-controlled trials 1
  • The most effective oral antiviral regimens include:
    • Famciclovir: 1500 mg as a single dose for 1 day 1
    • Valaciclovir: 2 g twice daily for 1 day 1
    • Aciclovir: 400 mg five times daily for 5 days (when taken during the tingling stage) 1
  • These medications significantly reduce healing time and duration of symptoms when started early in the course of an outbreak 1
  • For best results, treatment should be initiated at the first sign of a cold sore (during the prodromal or tingling phase) 1

Topical Antiviral Options

  • Docosanol 10% cream is FDA-approved as an over-the-counter treatment for cold sores 2
  • Directions for docosanol use:
    • Apply to affected area at the first sign of cold sore/fever blister (tingling sensation)
    • Use 5 times a day until healed
    • Early treatment ensures the best results 2
  • Docosanol works through a unique mechanism involving viral fusion inhibition 3
  • While effective, topical treatments are generally less effective than oral antiviral medications 4

Treatment Selection Considerations

When to Use Oral Antivirals

  • For more severe or frequent outbreaks 1
  • When faster healing time is a priority 1
  • For immunocompromised patients 1
  • When pain and symptoms are significant 1

When to Use Topical Treatments

  • For milder cases 2, 3
  • When oral medications are contraindicated 3
  • For patients who prefer over-the-counter options 2
  • For children over 12 years (for docosanol) 2

Important Clinical Considerations

  • Starting treatment at the earliest sign of symptoms (prodromal phase/tingling) is crucial for maximizing effectiveness of any treatment 1, 2
  • Recurrent episodes may benefit from prophylactic therapy with daily oral aciclovir or valaciclovir 4
  • For children under 12 years, consult a doctor before using docosanol 2
  • Lifestyle measures remain an important component of herpes management 5
  • Avoid touching or picking at lesions to prevent secondary infection or spread to other areas 1

Treatment Efficacy Comparisons

  • Oral antivirals reduce healing time by approximately 1-2 days compared to placebo 1, 4
  • Famciclovir 1500 mg single dose significantly reduced time to return to normal skin (2.9 days vs 4.5 days with placebo) 1
  • Topical docosanol reduces healing time by less than one day compared to vehicle control 5, 6
  • The trend in clinical practice shows increasing use of valaciclovir and decreasing use of aciclovir over time 7

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Docosanol: a topical antiviral for herpes labialis.

Expert opinion on pharmacotherapy, 2004

Research

Nongenital herpes simplex virus.

American family physician, 2010

Research

Topical n-docosanol for management of recurrent herpes labialis.

Expert opinion on pharmacotherapy, 2010

Research

Patterns of disease and treatment of cold sores.

The Journal of dermatological treatment, 2013

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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