Some people call it a cold sore, others a fever blister, but this annoying and the often painful chronic condition is caused by a virus: herpes simplex. About 50% to 80% of U.S. adults have oral herpes. According to the National Institutes of Health (NIH), by age 50, about 90% of adults have been exposed to the virus. Once infected, a person will have the herpes simplex virus for the rest of his or her life. When inactive, the virus lies dormant in a group of nerve cells. Some people never have any symptoms from the virus. Others have periodic outbreaks of infections.
The herpes lesions typically last a week to 10 days. It most often occurs around the lips, oral mucosa, or tongue. The lesions occur first as fluid-filled blisters that rupture after a day or two. The sores will weep fluid that contains the virus. After a few days, the sores will form crusts or scabs. The virus is highly contagious and can be spread by skin-to-skin contact such as kissing.
The 2 most common forms of the virus are herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). HSV-1 is most often linked with infections of the oral cavity, with up to 90% of people in the U.S. exposed to this virus. HSV-2 is most often associated with genital herpes infections, with up to 30% of people in the U.S. exposed to this virus. However, both types of HSV can infect both the mouth and the genitals.
Since HSV is spread through direct, physical contact, such as kissing and sexual contact, the best method of prevention is to avoid physical contact with the HSV sores when someone is having an outbreak. However, genital herpes can be contagious without causing any symptoms of the disease, according to the CDC.
The initial (primary) infection of the oral herpes simplex virus is usually the worst. It may cause severe, flu-like symptoms, swollen lymph nodes, and headache. However, some people have no symptoms at all. In the initial infection, sores can occur on and around the lips and throughout the mouth.
Recurring infections tend to be much milder, and the sores usually erupt in the edges of the lips. Some people never have any more outbreaks beyond the initial infection. These are the most common signs and symptoms of a recurring oral herpes simplex virus infection:
The signs and symptoms of an oral herpes simplex virus outbreak may look like other conditions or medical problems. Always see your physician for a diagnosis.
It is not clear what triggers the virus to recur, but several factors are thought to play a role. Prolonged or intense exposure to sunlight, a recent fever, emotional stress, menstruation, surgery, or physical injury might contribute to a recurrence of the virus. Recurrent outbreaks are more common in the first year after the initial episode, then lessen as the body builds antibodies to the virus.
Herpes simplex virus is difficult to diagnose. Often confused with many other infections, such as allergic reactions, the herpes simplex virus can only be confirmed with a virus culture, blood test, or biopsy. However, your physician can often diagnose it based on the location and appearance of the blisters.
Your physician will figure out the best treatment based on:
Treatment may involve: