Suggest Treatment For A Brown Rash On The Penis Head

I am 19 I have a brownish - pink dark patch at the back of my penius head. Like a ring... It looks like a darkened skin colour. I might have had this for over a year. I don t remember what my penius gland colour was.the first time I pulled my fore skin back was at 16,I have Phimosis, I can only retract the foreskin when it s not errict. So I rarely see my glands, and when I do its usually for few seconds to clean it. Which i do once or twice a week. my penius is also wrinkly , it doesn t hurt. The only thing I m really worried about is that my penius head (where the ring is) is softer than the penius body/shaft. When errect the tip of the penius body is hard , the tip(pee hole) of the head little hard BUT the upper/back glands where the ring is, is usually soft.