After having sex with my wife, I noticed the next day a small rash on the top-side of the shaft of my penis, it is also a little raised. I do not see any blisters or pimple like white heads. It is a little itchy once in a while, but it doesn't burn/hurt at all and minor friction from clothes does not bother it. The small rash is not even pea sized. I figure this is some kind of dry skin condition from having sex, a minor infection, or something along those lines. Any info or suggestions would be great, if it lasts for about a week I do plan on going to the doctor.