Cold sores are
blisters on the lips and the edge of the mouth that are caused by an infection
herpes simplex virus (HSV).
blisters usually break open, weep clear fluid, and then crust over and
disappear after a few days.
Other symptoms may include:
- A sore mouth that makes eating, drinking, and
sleeping uncomfortable. Cold sores can be painful.
- A sore throat.
lymph nodes in the neck.
- Drooling, in
You may not develop cold sores when you are first infected
with HSV. If cold sores do develop when you are first infected, they may be
more severe than in later outbreaks. During the first outbreak of cold sores,
the blisters may spread to any part of the mouth.
After you become
infected, HSV remains in your body and may cause cold sores to return
throughout your lifetime (recurrent cold sores).
Recurrent cold sores usually develop where
facial skin and the lip meet. About 6 to 48 hours before a cold sore is
visible, you may feel tingling, burning, itching, numbness, tenderness, or pain
in the affected area. This is called the prodromal stage.
common triggers that cause cold sores to return include:
People who have weakened immune systems are more likely
than those with strong immune systems to have longer or more severe outbreaks
of cold sores. HSV infection may be life-threatening in certain people who have
weak immune systems.
Who is at greatest risk for developing cold sores?
Anyone who is exposed to the herpes simplex virus (HSV) is at risk for
developing cold sores. But many people have the virus and may never develop
People who have weakened immune systems are at an
increased risk for having more severe and longer-lasting outbreaks of cold
One form of HSV infection is seen most often in children 1
to 3 years old. This type of HSV infection (primary herpes stomatitis) can
cause a high fever and blisters throughout the mouth, which can interfere with
the ability to eat. It can be serious in children—they can get quite sick from
this illness, although they usually recover without any long-term problems.