is there an STI that starts with a itching around the mouth, after oral? I went down on someone last night (drunken mistake

) Anyway today my lips and the outside of my mouth have started to itch and there are small rash like spots..although only a few. I was thinking it's too early for anything to show up though, isn't it?
Sorry I know this thread is a bit skanky...i guess it could be hayfever, like a pollen rash?