So I have this itchy red skin right next to the top part base of my penis, but not actually on the penis itself. It IS NOT AN STI. I know this because I have had it before when I was younger. Last time my doctor had no clue what it was but it went away but has come back a few years later. This time it popped up like a day after sex with my gf. It comes with an odor a slight odor as well. Any guesses?