University of Iowa Health Science Relations and
Patricia Winokur, MD
Associate Professor of Internal Medicine
First Published: November 2000
Peer Review Status: Internally Peer Reviewed

It never fails. You have a major event planned--a wedding, a party, a family photo. A couple of days before the big event, you feel that tale-tell tingling on your lip, and you know you're going to have a cold sore, just in time for photos.

Cold sores--annoying and unattractive blisters--appear next to or on your lip, and seem to come at the most inopportune times.

"Cold sores are caused by a common virus passed from person to person through touch or close contact. The virus is called herpes simplex type 1, HSV-1," says Dr. Patricia Winokur, assistant professor of internal medicine at the University of Iowa College of Medicine and staff physician at UI Hospitals and Clinics.

There are two types of herpes simplex viruses--HSV-1 and herpes simplex type 2, HSV-2. HSV-1 most commonly causes the sores on your mouth, Winokur explains. HSV-2 is usually sexually transmitted and often causes sores on the genitals.

Since the herpes virus is transmitted by touch, you can get the virus by touching someone else's cold sore and then touching your own mouth, Winokur says. "If you have a cold sore, and you kiss someone, you can pass the virus to the person you kiss."

People are usually infected with HSV-1 when they are children. The virus may remain latent--dormant or "sleeping"--during childhood and then reappear in later life. "Episodes of cold sores recur when something causes trauma to your mouth. Chapped or sunburned lips, stress, illness, poor diet, and not enough sleep also can trigger an outbreak," Winokur says.

The best way to prevent a cold sore from recurring is to take care of yourself. "Eat well, get enough sleep, use sunscreen on your face and lips. Try to relax when situations are stressful. Practicing these good habits may reduce the chances a cold sore will recur, but it is not always fool-proof. Cold sores can recur without any clear cause."

There is no medical cure or home remedy for cold sores, but the prescription medication acyclovir in some cases can lessen the number of outbreaks and shorten the course of cold sores. Aspirin or acetaminophen can relieve the discomfort associated with cold sores.

"Your best bet is to let it heal naturally," Winokur says. "The less you touch it, the less likely you are to transmit the virus to other parts of your body or infect the sore with common skin bacteria. Usually a cold sore will heal on its own in about one week."

For more information about cold sores, talk to your physician.