Cold sores are small and painful blisters that usually erupt around a person’s lips, although they can show up on any part of the body. A symptom of oral herpes, cold sores are caused by the herpes simplex virus type 1 (HSV-1). (Genital herpes, on the other hand, is usually a result of herpes simplex virus type 2.) Once you’ve been infected with HSV-1, you may experience recurrent cold sores throughout the rest of your life.
According to the American Social Health Association, it is estimated that about 90% of the American population contracts oral herpes by the time they reach age 50. Most people get oral herpes when they are children, often through close contact with an infected adult. Not everyone with oral herpes experiences cold sores.
How Oral Herpes Spreads
Oral herpes is very contagious. When you have a cold sore, you can easily infect another person if your cold sore touches a cut on their skin or any of their mucous membrane tissues such as the mouth or genitals. Infection can also occur if you touch your cold sore and then touch a susceptible area on another person. For this reason, oral herpes can be spread through sharing such items as utensils, drinks, or lip balm. Although the virus is most contagious when cold sores are present, it’s also possible to spread oral herpes when there are no symptoms, as the virus sometimes reactivates and reaches the skin without causing cold sores.
How HSV-1 Causes Cold Sores
After you’ve been infected with HSV-1, the virus usually goes dormant in your body for a long time. At some point, the virus reactivates and uses your nerve pathways to travel to a certain area of skin, usually around the lips but also commonly elsewhere on the face or inside the mouth. Many people experience burning or tingling for a day or two before the cold sore appears. After the cold sore heals, the virus goes dormant again; it may reactivate at a later date to cause another cold sore.
Reactivation of the Virus
Doctors aren’t sure what causes the virus to reactivate. Sometimes it’s in response to stress, other infections, hormonal changes, sun exposure, or certain drugs or food. Not all reactivations result in cold sores, as sometimes the virus wakes up and spreads to the skin without causing any noticeable symptoms. Many people with oral herpes either don’t ever experience a cold sore or do not experience a recurrence after their first outbreak.
There is no cure for oral herpes or for cold sores. Luckily, cold sores usually clear up on their own within seven to ten days. If you experience frequent cold sores, your doctor may prescribe an antiviral medication to help prevent cold sores or shorten their duration. You can help to alleviate the discomfort of your cold sores by using over-the-counter ointments and pain medication or by applying a cold compress to the affected area.