Hi, I have a problem with the skin on my penis , I masturbate a lot and the skin has changed colour, it appears to be dirty but I ve never been able to clean it off. It seems to be dirt because its worse in places where I put my hand , is there anything I can do about this? It makes it almost impossible to have a relationship, and I m too embaressed to see my regular doctor as I ve known her 25 years. Thanks in advance