Hi, I was just recently diagnosed with jock itch by a PA that I saw at a dermatology office. I noticed the tip of my penis is also somewhat red, can it spread to the tip? I did not mention this to the PA because I did not notice until I got home. Could it be an std? I have sex with one girl(my girlfriend) that I know does not have any diseases. It is red, is NOT itchy, and does not seem irritated until I think about it. What could this be?