Mouth ulcers are a form of herpes

[williaam]

I haveheard that a fever blister can be passed to the genitals and turn in t genital herpes. I have never had a fever blister but I often have mouth ulcers and so does my boyfriend. Can mouth ulcers be passed kissing? oral sex?

[asteroid99]

I've answered your other question on this subject.
I'm not sure what a fever blister is, but if it's a cold sore then thats a form of herpes and can be passed on through kissing and oral.
Mouth ulcers do not cause herpes.

[jen157]

If it's a cold sore which is HSV-1 than it can be transmitted to your genitals. According to this Herpes Site