Cold Sores (Orofacial Herpes):
Information for adults

Herpes simplex infection of the mouth and face, known as orofacial herpes simplex, herpes labialis, cold sores, or fever blisters, is a common, recurrent skin condition associated with infection by the herpes simplex virus (HSV). Orofacial herpes simplex virus usually appears as small blisters or sores around the mouth, nose, genitals, and buttocks, though infections can develop almost anywhere on the skin. Furthermore, these cold sores may come back periodically in the same sites.

Infections with the herpes simplex virus are very contagious and are spread by direct contact with the skin lesions. There are 2 types of HSV: Type 1 and Type 2. HSV Type 1 (HSV-1) infections usually occur around the mouth, lips, nose, or face, while HSV Type 2 (HSV-2) infections usually involve the genitals or buttocks. However, HSV-1 can sometimes cause infections in the genitals or buttocks, while HSV-2 can occasionally cause infections around the mouth, lips, nose, or face.

Both types of herpes simplex virus produce 2 kinds of infections: primary and recurrent.  Because it so contagious, the herpes simplex virus causes a primary infection in most people who are exposed to the virus. However, only about 20% of people who are infected with HSV actually develop visible blisters or sores. Appearing 2–12 days after a person's first exposure to HSV, the sores of a primary infection last about 1–3 weeks. These sores heal completely, rarely leaving a scar. Nevertheless, the virus remains in the body, hibernating in nerve cells.

Certain triggers can cause the hibernating (latent) virus to wake up, become active, and travel back to the skin. These recurrent HSV infections may develop frequently (every few weeks), or they may never develop. Recurrent infections tend to be milder than primary infections and generally occur in the same location as the primary infection.

Most people get cold sores as children, through contact with a friend or family member who is already infected with the herpes simplex virus. It can be spread (transmitted) by kissing, sharing eating utensils or drinking vessels, or by using the same towel.