Hello, Doctors. I do really appreciate your help, I have recently noticed that some of my penis head is covered by a different dark skin, it is like it has taken a darker skin than it was before. This has really made me depressed, it makes me psychologically uncomfortable. I don t have swelling, redness, itching or any thing that bothers me except that sometimes there is a little pain on the head of the penis(not while peeing). I am 21 and have never had sex in my life. Is that a sign of a dangerous disease?