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.[71] Changes in the immune system during menstruation may play a role in HSV-1 reactivation.[72][73] 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'.
The herpes virus can be shed from an infected person even when there are no lesions visible. So caution is important. Some may wish to take the daily prophylactic oral drug Valtrex (an antiviral oral medication) to help cut down on shedding. Herpes can also be transmitted on any skin: fingers, lips, etc. Depending on sexual practices, herpes simplex can be transferred to genitals and or buttocks from the lips of someone who has fever blisters. Honesty between partners is very important so these issues can be discussed openly.

How to get rid of a cold sore The herpes simplex virus that causes cold sores, often on people’s mouths, is highly contagious and a lifelong infection with no cure. Learn about how to treat cold sores when they appear, including anti-viral tablets and creams and home remedies, plus the life cycle of the virus, and how to prevent its spread. Read now
Cullins explains that even if you’ve never had an outbreak, if you’ve been exposed to herpes, it lies dormant in your body. A blood test could reveal antibodies for HSV-1 and/or HSV-2, which means that you have been exposed to the infection in your past, you have been infected, and you have developed antibodies because your body has or is fighting the infection.
HSV-2 is commonly referred to as genital herpes because it usually causes cold sores to erupt around the genitalia. In fact, genital herpes is the No. 1 cause of genital ulcers worldwide, according to the Centers for Disease Control and Prevention (CDC), and affects up to 1 in 3 adults (although most who are infected don’t even know it). (5) Both types of herpes viruses are highly contagious, and both can cause cold sores in either area of the body (or sometimes both). 

If you find out your partner has genital herpes, support him or her, and protect yourself. Genital herpes is so common and it may involve more than the virus itself. You can catch the disease from your partner through sexual contact. Without treatment, genital herpes can go away on its own. But, your partner needs medications to stop symptoms and prevent transmission. If you think the disease is harming your relationship, talk to your doctor for help.


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.[49] A female condom can provide greater protection than the male condom, as it covers the labia.[50] The virus cannot pass through a synthetic condom, but a male condom's effectiveness is limited[51] 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.[52] The risk is not eliminated, however, as viral shedding capable of transmitting infection may still occur while the infected partner is asymptomatic.[53] 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.[14] Topical microbicides that contain chemicals that directly inactivate the virus and block viral entry are being investigated.[14]
A doctor will base a presumptive diagnosis on information provided by the patient and on the physical examination. The characteristic appearance of the herpes sores leaves little doubt about the diagnosis, so the typical appearance of the sores is key to the diagnosis. This appearance helps distinguish oral herpes from oral thrush, shingles, gonorrhea, and syphilis. In addition, chapped or sunburned lips can resemble oral herpes, but the tissue stain (Tzanck smear, see below) shows no virus-induced cell changes. Further testing is usually not necessary but is sometimes done.
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