There is dark grey colored skin going from my testicles to my glans, when irritated by things such as rubbing it turns red, also noticed a dead vein near it. Also the closest affected part to the glans it seems to sort of be making a ring. The line of skin is only on my left side of my penis, and gets wider closer to the testicles. It also has a different, smoother, and slightly stickier texture to it. Towards the testicle side of the penile shaft there is a small crease. The closest thing I could find online to this issue is friction burn? Unless an STD can be carried from birth and only show up after so many years. I have never had sex so I'm assuming it was caused by masterbation. Any information on what it is and how to heal it would be greatly appreciated!