Hi, thanks for writing in with your concerns. The herpes swab from the area affected ( in your girlfriends case – the blisters) is the most accurate way of testing for herpes. It will tell if its herpes or shingles, what type of herpes and the person will know where the herpes is on their body. Blood testing for herpes will tell if a person has come in contact with herpes, what type of herpes but not which area of their body it is on. Its possible to have herpes for a long period of time without any outbreaks and then when the immune system is stressed, the herpes will come out in an outbreak and it will seem like it just appeared but really it has been present for a long time. Diabetes can weaken a persons immune system especially if it is not well controlled and a suppressed immune system makes them more vulnerable to infection like herpes and bladder infections and yeast infections. So it is also possible that you have carried genital herpes without knowing it and passed it to your girlfriend or you carry herpes around your mouth with or without coldsores and transmitted it through giving her oral sex. Having a herpes outbreak can also affect a persons diabetes by altering blood sugar levels. There are resources on our website for herpes but not for diabetics with herpes. In this case, I suggest if your partner is agreeable, that you go with her to her doctor so that you can both ask any questions about the effect of herpes and diabetes adn how you can best support her.
Let us know if this does not answer your question or if you have any more questions or concerns.