General Information

• Cause: Cold sores are recurrent painful blisters on the outer lip caused by the Herpes simplex virus (usually Type I).
• Primary Herpes Simplex: Approximately 80% of the adult population has had herpes simplex at some point in their lives. The very first episode (primary herpes simplex) of infection can present as sores on the inside of the mouth (with fever and feeling sick). More commonly, people have no symptoms at all during the first episode.
• Recurrent Herpes Simplex Labialis (Cold Sores): After the first episode of Herpes, the Herpes virus stays hidden in a facial sensory nerve. It can be reactivated by sun exposure, fever, friction, trauma, menstrual periods, stress or physical exhaustion. Such recurrences occur in 20% of the adult population. Typically, the symptoms are confined to the lip and there is no fever. The medical term for these recurring cold sores of the lip is Herpes Simplex Labialis. Another term that people use for this condition is Fever Blisters. This is a self-limiting illness that resolves without any treatment in 7 -10 days.