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Diseases and Conditions
Cold soreFrom MayoClinic.com
Special to CNN.com
The scenario is all too familiar: You feel a tingling on your lip and a small, hard spot that you can't yet see. Sure enough, in a day or two, red blisters appear on your lip. It's another cold sore, probably happening at a bad time, and there's no way to hide it or make it go away quickly.
Cold sores — also called fever blisters — are quite different from canker sores, a condition people sometimes associate them with. Cold sores are caused by the herpes simplex virus, and they're contagious. Canker sores, which aren't contagious, are ulcers that occur in the soft tissues inside your mouth, places where cold sores don't occur.
Cold sores are common. Though you can't cure or prevent cold sores, you can take steps to reduce their frequency and to limit the duration of an occurrence.
Signs and symptoms
Signs and symptoms of cold sores include:
Cold sores usually appear on your lips. Occasionally, they occur on your nostrils, chin or fingers. And, although it's unusual, they may occur inside your mouth — but only on your gums or hard palate, which is the roof of your mouth. If the sore appears on other soft tissues inside your mouth, it may be a canker sore, but it's not a cold sore.
Signs and symptoms may not start for as long as 20 days after exposure to the herpes simplex virus, and usually last seven to 10 days. The blisters form, break and ooze. Then a yellow crust forms and finally sloughs off to uncover pinkish skin that heals without a scar.
Certain strains of the herpes virus cause cold sores. Herpes simplex virus type 1 usually causes cold sores. Herpes simplex virus type 2 is usually responsible for genital herpes. However, either type of the virus can cause sores in the facial area or on the genitals. You get cold sores from another person who has an active lesion. Shared eating utensils, razors and towels may spread this infection.
Once you've had an episode of cold sores, the virus lies dormant in the nerve cells in your skin and may emerge again as an active infection at or near the original site. You may experience an itch or heightened sensitivity at the site preceding each attack. Fever, menstruation, stress and exposure to the sun may trigger a recurrence.
When to seek medical advice
Cold sores generally clear up on their own without treatment. However, see your doctor if:
Cold sores are contagious. They can pass from one person to another through skin-to-skin contact. The greatest risk of infection is from the time the blisters appear until they have completely dried and crusted over. There is a possibility of spreading the virus for some time even after the skin has healed.
If you have a cold sore, avoid close contact with infants, anyone who has eczema (atopic dermatitis) or people with a suppressed immune system, such as people with cancer, AIDS or an organ transplant. These people are at higher risk of more severe infection.
Herpes simplex infection of the eye causes scarring of the cornea and is a leading cause of blindness in the United States.
Cold sores generally clear up without treatment in seven to 10 days. If you experience frequent bouts, your doctor may prescribe an antiviral medication to treat cold sores. Using a medication may shorten the duration of cold sores and decrease your pain.
You can take steps to guard against cold sores, to prevent spreading them to other parts of your body or to avoid passing them along to another person:
Cold sores generally clear up without treatment. In the meantime, the following steps may provide relief:
March 13, 2006