What Is a Cold Sore on the Lip?

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Cold sores, or fever blisters, are lesions that may develop on the outside of the mouth, including the lip, chin and cheeks. Cold sores also occur inside of nostrils and may be painful and unsightly. The Type 1 herpes simplex virus causes cold sores. The herpes simplex virus is contagious, and some infected individuals may never show symptoms of infection.

Cold Sore Infection

The initial infection is contracted by both direct and indirect contact with the virus. Direct infection may occur through kissing or other direct contact with the blister. Indirect infection may occur through contact with washcloths, towels, razor blades and other items. During the initial infection, the sore usually occurs within 7 to 21 days of contact with the infected item or person. The sore may be red, crusty or fluid-filled. Also, a mild fever may occur during active infection. Subsequent outbreaks tend to be milder than the initial outbreak following infection.

Cold Sore Prevention

Prevent contracting cold sores by avoiding contact with herpes lesions. This includes avoiding receiving oral sex from a person with cold blisters. Also avoid sharing items such as towels or razor blades with infected individuals. Infection risk becomes greater when an individual has active blisters. If you share items with an infected person, wash the items well in hot or boiling water. The herpes virus is transmittable even when the infected individual has no active lesions.

Cold Sore Treatment

As of 2009, there is no cure for the herpes virus. Treatment may reduce the irritation and discomfort of the symptoms. Avoid spreading cold sores to other areas of the skin by gently washing the blisters with soap and water. Topical medications help by numbing the area to reduce the pain of the blister. Antiviral medications work to decrease the amount of outbreaks that occur. Antibiotics prevent cold sores from developing into bacterial infections. Untreated cold sores usually resolve within 7 to 14 days.

Cold Sore Complications

Cold sore infections may be life-threatening in people with compromised or suppressed immune systems, such as HIV-positive individuals. Blindness may occur if the herpes virus infects the eyes. According to the National Institute of Health Medical Encyclopedia, as of 2009 herpes eye infections are the leading cause of blindness in the United States.