Clinical Reference Systems: Pediatric Advisor 10.0
Cold Sores (Fever Blisters)
- a cluster of painful 1- to 3-mm bumps or blisters on the
- on one side of the mouth only
- tingling or burning on the outer lip at the same site
where cold sores previously occurred.
Cold sores are caused by the herpes simplex virus (usually
Type 1). The first bout follows contact with someone with
herpes. Thereafter, the cold sores recur in 2% of people
when the virus (which lives in the sensory nerve) is
reactivated by sunburn, fever, friction, or physical
The blisters will rupture, scab over, and dry up. The whole
process takes 10 to 14 days. The sores do not cause scars.
Treatment can shorten the course by many days.
- Antiviral ointment
Once you get fever blisters, you usually can't shorten
the time that you have them unless you start applying an
antiherpes ointment as soon as any small bumps appear.
These ointments require a prescription. If you don't
have an antiherpes ointment, cover the fever blisters
with petroleum jelly to reduce the pain and to promote
Your child needs the ointment prescribed by your
physician. The ointment can reduce the severity of the
sores only if treatment is started early.
Since fever blisters are often triggered by exposure to
intense sunlight, prevent them in the future by using a
lip balm containing sunscreen. If blisters are not yet
present, apply an ice cube or ice pack to the tingly
area continuously for 90 minutes. This will sometimes
abort the infection.
Avoid spreading this germ to another person's eye
because an infection there can be serious. Therefore,
discourage picking, and wash the hands frequently.
Since the condition is contagious, have your child avoid
kissing other people during this time. If your child is
young and puts everything in his mouth, avoid sharing
toys with other kids for a week.
If your teenager is going skiing or to the beach and has
had frequent herpes flareups in the past, despite
careful use of sunscreen, call your physician. Recent
research has found that starting oral antiherpes
medication (pills) before such outings can prevent most
CALL YOUR CHILD'S PHYSICIAN DURING OFFICE HOURS IF:
- Any sores occur near the eye.
- The sores last longer than 2 weeks.
- You have questions about antiherpes ointments.
- You have other concerns or questions.