So it's not that noticeable, and my guess is that it's dry skin or eczema or something, but you really need to let your doctor see it. No one can diagnose you from a pic online.
You don't mention anything about risk factors for STDs, but if you are concerned about those, you need to test.
Your doctor has seen far "worse" things than some dry patches on a penis, I promise.
If you are sexually active, and haven't ever tested for STDs, now is a good time, right?
Don't try to treat this yourself. If you use the wrong thing, you could make it a lot worse. Just go get it checked out. You can do this. :)