Cold Sores (Fever Blisters)

    Updated at May 23rd, 2024

    Disclaimer [ENGLISH]


    DisclaimerThis material is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it. It is not intended to provide medical advice, diagnosis or treatment, nor does it replace the advice or counsel of a doctor or health care professional. Reference to a specific commercial product or service does not imply endorsement or recommendation of that product or service by CPCMG.


    What is a cold sore (fever blister)?

    • These are sores or blisters that usually form on or around the lips.
      • They can also appear on the cheeks, nose, or chin.
    • Usually, they are grouped together into clusters.  
    • They are caused by a virus called herpes simplex virus.
      • Even though they are called “cold” sores, they are not caused by common colds.  
    • Most children are exposed to these viruses between the ages of 1 and 5 years old.
    • Nearly half of the people in the U.S. have had herpes by the time they are an adult.
    • You get them from contact with the virus.
      • This can happen if you touch a sore or touch a hand that has touched the sore.
      • You can also get herpes if you share food, drinks, or utensils with another that is infected.  
    • The virus stays in the nerves of the face once infected and that is why your child can have infections again.  

    What are the symptoms of cold sores?

    • There is usually a tingling, itching, or burning feeling before the sores develop.
      • You may notice your child touching or itching at a spot on their face during this time.
    • Once the sores develop, they usually last for 2 to 10 days (about 1 and a half weeks) and resolve on their own.
      • Your child might continue to complain of pain, itching, or burning until the sores are starting to heal.
    • They usually look like fluid-filled blisters and as they heal, they look like crusts and then scabs.
    • If this is the first time your child has the infection, their symptoms might also include a fever or swollen lymph nodes in their neck.  
      • First time infections are also more likely to be more widespread including sores inside the mouth.
    • If you see any sores close to your child’s eye, contact your child’s provider.
    • If your child is under 6 months contact your child’s provider.  
    • Your child may complain of pain in their mouth or throat, and they might drool more.
    • Your child may be more irritable because of the discomfort.
    • Your child may eat or drink less due to the pain. 
    Stages of a cold sore outbreak.

    What is the treatment for cold sores?

    • Encourage lots of fluids to make sure your child stays hydrated.
    • Tylenol or ibuprofen (6 months and older) may help with the pain and discomfort.  
    • Cool compresses on the sores may help ease the discomfort.
    • Avoid acidic (like citrus fruits and tomato sauce) and spicy foods -   - they may irritate the sores even more.
    • Cold or icy drinks like smoothies or healthy popsicles may be helpful.  
    • Anti-viral medications (acyclovir is an example) are sometimes used.
      • Symptoms when your child might be prescribed medication: fever, marked discomfort in their mouth or pain in their neck due to swollen lymph nodes.
        • These symptoms are more common during the first infection.  

    What can I do to prevent my child from getting this infection?

    • Accordion Encourage lots of good hand washing.
    • Be sure to clean high contact surfaces regularly.
    • Avoid sharing any food, drinks, or utensils with others.
    • While your child has cold sores, remind them to avoid touching them.
      • If touched wash hands right away.
    • If you have cold sores as a parent or caregiver avoid any contact with the sores and your child. Recurrences can happen if your child gets sick often, is struggling with emotional stress, or has been exposed to drastic changes in temperature.  
      • Be sure to apply sunscreen regularly.  
      • Avoid excessive heat, cold temperatures, or dryness.
      • Provide a well-balanced diet.
      • Encourage good sleeping habits.
      • Encourage regular exercise.
      • Help your child manage stress.
        • Check out this article for additional helpful tips  
    • Keep your child’s skin moisturized, breaks in the skin can increase the chance of cold sores.
    • If your child has cold sores frequently, an anti-viral medication (example: acyclovir) may be helpful for prevention. Please discuss this with your child’s provider. Body

    When to contact your child’s provider:

    • Your child is under 6 months of age.  
    • Your child has any lesions near their eye.  
    • This is the first time your child has cold sores.  
    • Your child continues to have frequent or recurring outbreaks of cold sores.  
    • Your child has a fever for five days.
    • Your child’s sores are getting worse or have pus in them.
    • Your child is refusing liquids.
    • You have other questions, concerns, or think your child needs to be seen.  

    This publication was adapted from information within American Academy of Pediatrics Patient Education Handouts, UpToDate Guidelines, and

    Reviewed by: TT D.O, AR D.O. | 01/2024