I occasionally notice a round patch of lighter colored, unraised skin on the head of my penis which is most strongly evident soon after masturbation or during periods when my masturbation habits are on the up. It is not perticularly painful or itchy but occasionally twinges, almost tickles. In looking at the way I hold my hand during masturbation, I realized that it could be due to the fact that the said location is often subject to most of the rubbing during masturbation, however I am worried that it may be something more sinister (during the last term at college I had unprotected sex with a partner with whom I am not in contact with, and odds are never will be again.) I've checked images of the most common STDs (Herpes, HPV, Genital Warts) and none of them look like this (All three are generally raised and differ greatly from the color of the skin, whereas this is not raised and is only a slight variation in skin color).
There is little to no trouble during urination, nor is there any particular pain, except occasionally there is a slight soreness directly after masturbation. There is no puss or discharge from either the penis or from the area of discoloration, nor is the area significantly different in smoothness and texture from the skin around it.
This discussion is related to
Discoloration on Penis.