Cold sores, which are also called fever blisters, are groups of fluid-filled blisters that often erupt around the lips and sometimes under the nose or around the chin. Cold sores are caused by the herpes simplex virus type 1 and are very contagious. The initial infection (primary herpes) may be confused with a cold or flu and can cause painful lesions to erupt throughout the mouth. Once a person is infected with primary herpes, the virus stays in the body and causes occasional attacks.
Cold sore blisters usually heal in a week by themselves. Over-the-counter topical anesthetics can provide some relief. Your dentist may prescribe antiviral drugs to reduce these kinds of viral infections.
