Health A to Z

Cold sores

They’re unsightly, contagious and painful. Here’s how to treat them.

Cold sore treatment prevention causes

Just like pimples, cold sores always seem to crop up whenever it’s least convenient – when you’re on vacation, before a big date or on the eve of an important work function. These painful fluid-filled blisters usually appear on the lips, chin, cheeks or nostrils or inside the mouth on the gums or the roof of the mouth.

Cold sore causes Cold sores around the mouth are caused by type 1 of a contagious virus called herpes simplex. Herpes simplex type 2 causes sores on the genitals, called genital herpes. Cold sores are contagious — often passed along through kissing, or sharing utensils, towels or other personal items. Engaging in oral sex with someone who has cold sores can lead to genital herpes. Sores usually appear within a week of exposure to the virus. After the initial exposure, the virus lies dormant in the body and may trigger another cold sore as a result of stress, menstruation, fatigue or sun exposure.

Cold sore symptoms A painful blister forms, breaks and oozes. A yellow crust then forms and sloughs off, revealing pinkish skin that heals without scarring.  Tingling may indicate that a cold sore is forming. The blisters usually last 10 to 14 days.

Cold sore diagnosis/tests If you’re frequently getting cold sores (six or more times annually) or you notice your eyes are hurting when you develop them, pay a visit to your family doctor, who will discuss your medical history, including if you have any conditions that may be weakening your immune system, such as pregnancy.

Cold sore treatment There is no cure for cold sores; typically the blisters clear up without treatment. Topical treatments, such as lidocaine, may provide pain relief. Oral antiviral medications may shorten the duration of a cold sore and prevent recurrences.

Cold sore prevention It may be possible to guard against cold sores and avoid spreading them to other people and other parts of your own body. Use sun block if you’re going to be spending prolonged time in the sun. Avoid your triggers, for example, not getting enough sleep, being overly stressed or excessive sun exposure. If you have a cold sore, do not kiss or have skin-to-skin contact with other people, which can spread the virus; and avoid sharing lipsticks, utensils or other items. Wash your hands frequently and do not touch your eyes or genitals which may be especially susceptible to the herpes virus.

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Outside resources
Mayo Clinic

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