Cold Sores (Fever Blisters)

Definition

  • Sores on the outer lip caused by the herpes virus
  • Sores tend to recur

Call or Return If

  • Sores occur near or in the eye
  • Sores last over 2 weeks
  • You think your child needs to be seen
  • Your child becomes worse

About This Topic

Symptoms

  • A cluster of painful, small bumps or blisters on the outer lip
  • The small blisters often rupture and form 1 big sore (cold sore)
  • Present only on one side of the lip. It doesn't cross the midline.
  • Cold sores are a problem that recurs (called flare-ups). They recur in the same place each time.
  • An early sign of a sore is tingling or burning on the outer lip.

Cause

  • Cold sores are caused by the herpes simplex virus type 1. It is passed to another after contact with someone with an open lip sore.
  • Once infected, the virus stays in the body. It can cause cold sores to recur.
  • The sores come back because of different triggers. Some are sunburn, fever, colds, lip friction, lip injury, menstrual periods and stress. Cold sores usually start 2 to 3 days later.

Prevention of Spread to Others

  • Herpes from fever blisters can spread to others.
  • Help your child not to pick or rub the sore. Don't open the blisters. Wash the hands often.
  • Since the blisters are contagious, avoid kissing other people during this time. Avoid sharing drinking glasses or eating utensils.
  • If your child is young and puts everything in the mouth, avoid sharing toys. Do this for a week.
  • Avoid contact with anyone who has eczema or a weakened immune system.
  • Teens. Avoid oral sex during this time. Herpes from sores on the mouth can spread to partner's genital area.
  • The person with cold sores cannot infect himself at other sites. Reason: Immunity protects the rest of the body.

After Care Advice

Overview:
  • Fever blisters or cold sores occur on one side of the outer lip.
  • They are a problem that recurs in 20% of normal adults. They are less common in children.
  • Cold sores can't hurt the person who has them. But, the virus can spread to others.
  • Cold sores are mainly a cosmetic problem.
  • You can treat cold sores at home.
  • Here is some care advice that should help.
Ice:
  • Use ice wrapped in wet cloth to the lip for 20 minutes.
  • Follow this with a wet tea bag (tannic acid) to the lip. Put this on for 10 minutes.
  • Do this once.
  • This home treatment may reduce the severity of the infection. You must start early before blisters are seen. This is usually when the lip is tingling or puffy.
Lip Ointment:
  • Apply a fever blister ointment 4 times per day. No prescription is needed. Ask your pharmacist to suggest one.
  • This also must be started as soon as any tingling or small bumps appear.
  • Until purchased, cover the fever blisters with a thin layer of petroleum jelly. This will help to reduce the pain.
Anti-Viral Medicine by Mouth:
  • Oral antiviral drugs may be helpful if started early. But, this is not standard practice. Reason: Fever blisters will go away on their own.
  • If your doctor has prescribed an anti-viral drug, take it as advised.
  • Try to start it when any small bumps appear and before they blister.
Pain:
  • For pain relief, give acetaminophen every 4 hours OR ibuprofen every 6 hours. Give as needed.
Prevention of Flare-ups of Cold Sores:
  • Fever blisters are often triggered by sun.
  • Use a lip balm with a sunscreen of 30 before being in the sun.
What to Expect:
  • The blisters will break open, scab over, and dry up. This takes 7 - 10 days.
  • After the sores are dry, your child is not contagious.
  • The sores do not leave scars.
  • Cold sores often recur 2 to 3 times per year. Flare-ups can last a lifetime.
Return to School:
  • Older children who have had cold sores before can go to school.
  • Young children with lots of sores may need to be kept home. Keep home until all sores are dry. If puts objects in mouth, avoid sharing toys for one week.