Does you boyfriend get cold sores? (usually herpes type 1, type 2 is usually the genital area but both types can infect either the mouth or genital area)
The kiss would not have cause it, the herpes virus generally takes at least a couple days to manifest into a blister and could be accompanied by swollen lymph nodes and fever.
There is no cure for a virus, but there are antivirals that will help to suppress it.
A culture test would confirm what it was, but it may have healed already. An IgG blood test will detect antibodies that develop a few months after exposure.
So this could be herpes, but it is not possible to tell for certain even after researching it. The next step is to see a professional.
at this point it's too late for any lesion cultures. even going to be seen at this point is probably futile.
it showed up a few hours after kissing your bf so if it is herpes, it's not a newly acquired infection. have you and your partner discussed std's and testing and such yet? do you recall if you've ever been tested for herpes bfore?
if this reoccurs, then is the time to be seen about it. try not to pop it before you are seen though I know sometimes that's hard for it not to happen on its own while eating and such.
help i have the same thing as mellyna. it looks like a clear bump on my lip and then it pops so easily and white puss comes out. then it re forms weeks or days later. and it looks like a little hole later