Cold sores are caused by the herpes simplex virus, and they're contagious. Signs and symptoms of cold sores include:
-Small, painful, fluid-filled blisters on a raised, red, painful area of your skin
-Pain or tingling, called the prodrome, often precedes the blisters by one to two days
-Usual duration of seven to 10 days
Cold sores usually appear on your lips. Occasionally, they occur on your nostrils, chin or fingers.
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.
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