Oral herpes is a viral infection mainly of the mouth area and lips caused by a specific type of the herpes simplex virus. Oral herpes is also termed HSV-1, type 1 herpes simplex virus, or herpes labialis. The virus causes painful sores on the upper and lower lips, gums, tongue, roof of the mouth, inside the cheeks or nose, and sometimes on the face, chin, and neck. Infrequently, it may cause genital lesions. It also can cause symptoms such as swollen lymph nodes, fever, and muscle aches. People commonly refer to the infection as "cold sores."
Following active infection, herpes viruses establish a latent infection in sensory and autonomic ganglia of the nervous system. The double-stranded DNA of the virus is incorporated into the cell physiology by infection of the nucleus of a nerve's cell body. HSV latency is static; no virus is produced; and is controlled by a number of viral genes, including latency-associated transcript.
As of 2017, there is not currently a herpes vaccine available to prevent HSV-1 or HSV-2. (There is a vaccine available for another virus, herpes zoster; however, despite the similar name, it actually refers to the shingles virus. And, in fact, shingles occurs due to the reactivation of yet another virus, varicella zoster, which causes chicken pox.)
If you think you have or have been exposed to herpes you should see your primary care provider for follow up, screening, and possible treatment. Many providers today will not test unless you have symptoms of an outbreak, as often tests come back as false positive and the CDC has concluded that false positives cause psychological trauma to those tested. There is much debate on if you should test without symptoms or not, others say it is unethical to not be aware of your current STD status and risk infecting other people.
The causes of reactivation are uncertain, but several potential triggers have been documented. A 2009 study showed the protein VP16 plays a key role in reactivation of the dormant virus. Changes in the immune system during menstruation may play a role in HSV-1 reactivation. Concurrent infections, such as viral upper respiratory tract infection or other febrile diseases, can cause outbreaks. Reactivation due to other infections is the likely source of the historic terms 'cold sore' and 'fever blister'.
Until the 1980s serological tests for antibodies to HSV were rarely useful to diagnosis and not routinely used in clinical practice. The older IgM serologic assay could not differentiate between antibodies generated in response to HSV-1 or HSV-2 infection. However, a glycoprotein G-specific (IgG) HSV test introduced in the 1980s is more than 98% specific at discriminating HSV-1 from HSV-2.
Genital herpes is contracted through sexual activity, and may show symptoms around the genital area (anus, buttocks, thigh, penis, vulva, etc.). Additionally, people with HIV can experience significantly worse symptoms of herpes. See a doctor if your partner has herpes, or if you notice any unusual sores on your body. How do you know if you have herpes? Read more in our Diagnosing Herpes section here.
After exposure to the virus, many people experience a so called primary infection which is typically associated with sores on or around the genitals or the anus. During a primary infection some people experience pain in the groins or a mild fever. Not all infected individuals experience a primary infection or show any symptoms at all, but they can still pass the disease on to other people.
Some people experience very mild genital herpes symptoms or no symptoms at all. Frequently, people infected with the virus don't even know they have it. However, when it causes symptoms, it can be described as extremely painful. This is especially true for the first outbreak, which is often the worst. Outbreaks are described as aches or pains in or around the genital area or burning, pain, or difficulty urinating. Some people experience discharge from the vagina or penis.
Condoms offer moderate protection against HSV-2 in both men and women, with consistent condom users having a 30%-lower risk of HSV-2 acquisition compared with those who never use condoms. A female condom can provide greater protection than the male condom, as it covers the labia. The virus cannot pass through a synthetic condom, but a male condom's effectiveness is limited because herpes ulcers may appear on areas not covered by it. Neither type of condom prevents contact with the scrotum, anus, buttocks, or upper thighs, areas that may come in contact with ulcers or genital secretions during sexual activity. Protection against herpes simplex depends on the site of the ulcer; therefore, if ulcers appear on areas not covered by condoms, abstaining from sexual activity until the ulcers are fully healed is one way to limit risk of transmission. The risk is not eliminated, however, as viral shedding capable of transmitting infection may still occur while the infected partner is asymptomatic. The use of condoms or dental dams also limits the transmission of herpes from the genitals of one partner to the mouth of the other (or vice versa) during oral sex. When one partner has a herpes simplex infection and the other does not, the use of antiviral medication, such as valaciclovir, in conjunction with a condom, further decreases the chances of transmission to the uninfected partner. Topical microbicides that contain chemicals that directly inactivate the virus and block viral entry are being investigated.
According to a study in the New England Journal of Medicine, more than 30% of pregnant women in the United States have genital HSV. During pregnancy, people are immunocompromised so that their body doesn’t fight the fetus as a foreign invader. And when a person’s immune system is weakened, they are more likely to have herpes outbreaks. According to Cullins, “Pregnancy is the time period when [a provider] really wants to know whether or not the person has had herpes in the past,” so they can protect the pregnant person and their infant from a herpes infection.