Although normally benign, a cold sore outbreak can be irritating and embarrassing. Understanding why they occur is the first step to minimizing outbreaks.

The typical cold sore (also known as a fever blister) is caused by the Herpes Simplex Virus (HSV) Type I, medically known as “Herpes Labialis” because it occurs on or around the lips. This virus is not to be confused with HSV Type II, which causes a genital infection. Unlike most viruses, HSV Type I can cause a recurring sore outbreak in certain people. Most viruses tend to occur only once because the body produces anti-bodies to prevent further attack; it’s believed HSV Type I, however, can shield itself from these defenses by hiding in the body’s nerve roots.

These cold sore outbreaks often occur during periods of high stress, overexposure to sunlight or injuries to the lip. Initially you may have an itch or slight burning around the mouth that escalates into more severe itching, redness, swelling and blistering. The sores will break out for about a week to ten days and then scab over and eventually heal (unless they become infected, in which case the healing process may go longer). You’re contagious between the first symptoms and healing, and so can spread the virus to other people.

In recent years, anti-viral prescription medications have been developed that can effectively prevent HSV outbreaks, or at least reduce the healing time after an occurrence. The most common of these are acyclovir and valcyclovir, proven effective with only a few possible mild side effects. They can be taken routinely by people with recurring cold sores to suppress regular outbreaks.

While HSV Type I cold sores are more an aggravation than a health danger, it’s still important for you to see us initially for an examination if you encounter an outbreak. It’s possible for a more serious condition to masquerade as a cold sore or blister. A visit to us may also get you on the right track to reducing the frequency of outbreaks, as well as minimizing discomfort when they do occur.

If you would like more information on the treatment of cold sores, please contact us or schedule an appointment for a consultation. You can also learn more about this topic by reading the Dear Doctor magazine article “Cold Sores.”