Cold sores (fever blisters) are caused by the herpes virus, usually type I.  They are small blisters that often produce drops of liquid and scab.  The fluid in the blisters contains the virus and you may pass the infection to other mucous membranes (eyes, genitalia, etc.) or to another person via this fluid.  About 80 percent of American adults have cold sores.

Cold sores most often appear on the lower lip or the outer edge of the mouth.  If you get cold sores, you were exposed to the herpes virus sometime in the past.  The virus remains inactive for varying lengths of time.

Cold sores may appear as a result of exposure to sunlight, fever, one's menstrual cycle, stress, or for no apparent reason.
 

Treatment

Herpes is a self-limiting virus and the cold sore will usually go away within 7 - 10 days untreated.  Symptoms can sometimes be relieved with ice or cornstarch moistened with water, and use of products containing camphor, such as as Blistex®, Campho-Phenique®, Carmex® Lip Balm, and Vicks® VapoRub.  You may be prescribed a medication (Zovirax® or others), which usually shortens the duration of the outbreak or can briefly prevent new outbreaks.
 

Tips to prevent the spread of the virus:

• Be sure you thoroughly wash your hands after any contact with the cold sore to prevent further spread of the infection in yourself or others

• If you wear contact lenses, do not use your saliva as a wetting agent for your lenses – it will spread the virus to your eyes (which are very vulnerable to the virus)

• Avoid all direct contact (kissing, oral sex, etc.) when you have a cold sore as you can spread herpes to another person.  The risk for exposing others to the virus when you do not have an outbreak is greatly diminished but still present.