, sometimes called
fever blisters, are groups of small blisters on the lip and around the mouth.
The skin around the blisters is often red, swollen, and sore. The blisters may
break open, leak a clear fluid, and then scab over after a few days. They
usually heal in several days to 2 weeks.
Cold sores are caused by
herpes simplex virus (HSV). There are two types of
herpes simplex virus: HSV-1 and HSV-2. Both virus types can cause sores around the mouth (herpes labialis) and on the genitals (genital herpes).
The herpes simplex virus
usually enters the body through a break in the skin around or inside the mouth.
It is usually spread when a person touches a cold sore or touches infected
fluid—such as from sharing eating utensils or razors, kissing an infected
person, or touching that person's saliva. A parent who has a cold sore often
spreads the infection to his or her child in this way. Cold sores can also be
spread to other areas of the body.
The first symptoms of cold
sores may include pain around your mouth and on your lips, a fever, a sore
throat, or swollen glands in your neck or other parts of the body. Small
children sometimes drool before cold sores appear. After the blisters appear,
the cold sores usually break open, leak a clear fluid, and then crust over and
disappear after several days to 2 weeks. For some people, cold sores can be
Some people have the virus but don't get cold sores.
They have no symptoms.
Your doctor can tell
if you have cold sores by asking you questions to find out whether you have
come into contact with the virus and by examining you. You probably won't need
Cold sores will
usually start to heal on their own within a few days. But if they cause pain or
make you feel embarrassed, they can be treated. Treatment may include skin
creams, ointments, or sometimes pills. Treatment may get rid of the cold sores
only 1 to 2 days faster, but it can also help ease painful blisters or other
The herpes simplex virus that causes cold
sores can't be cured. After you get infected, the virus stays in your body for
the rest of your life. If you get cold sores often, treatment can reduce the
number of cold sores you get and how severe they are.