Okay, let’s start off by clarifying that cold sores are a form of Herpes Simplex – Oral Herpes (HSV-1).
When someone has an outbreak, which is when they have a cold sore or a fever blister (whatever you want to call it), that’s when HSV-1 is the most contagious. When the symptoms/blisters are present, when they’re actually on your mouth, that’s when you can easily give it to someone else. Sharing a cup, sharing a towel, and yes, oral sex. If you have an outbreak and you perform oral sex on someone, you are opening them to a high risk of infection.
Oral herpes is transmitted through direct contact between the contagious area and broken skin (a cut or break) and mucous membrane tissue (such as the mouth or genitals). Herpes can also be transmitted when there are no symptoms present. There are several days throughout the year when the virus reactivates yet causes no symptoms (called asymptomatic shedding, viral shedding, or asymptomatic reactivation).
So if you have an outbreak, refrain from kissing on the mouth and performing oral sex until the sore heals and the skin goes back to normal. However, a large majority of the adult population already has HSV-1 and it’s asymptomatic for many.
There’s also a reverse! By performing oral sex on someone who has genital herpes, it would be possible to contract oral herpes – but that’s rare. Most cases of genital herpes are caused by HSV-2, which rarely affects the mouth or face.
However, you will likely contract HSV-2, genital herpes, if you perform oral sex on someone who has it, especially if they have any open sores around that area. I don’t want to freak people out, but yes, you can contract genital herpes EVEN WHEN THERE ARE NO VISIBLE SORES.
So oral herpes is a very mild disease, there’s no cure, but the biggest issue is largely cosmetic. Genital herpes, with the HSV-2 virus, however, is more painful, and can be worse if you have a suppressed immune system. The sores are easily transferred to other parts of the body so you have to be particularly careful. Wash your hands immediately if you touch a sore.
Oral and genital herpes are manageable conditions so don’t panic. Yes, you should take all the precautions you can, but if you do contract the virus, it’s not the end of the world.
Talk to your doctor!