You probably have jock itch. I have the same thing too and it has a burning sensation and red rashes around the groin area and scrotum skin.. Go buy some antifungal cream or gel.
I had red dry and sometimes itchy patch on the head of my penis. After some research I found Hydrocortisone creme once a day for a week made it go away completely. good luck.
I too have the flaky skin, irritation, red underneath, 1/3 of head and surrounding shaft. I used Triple-Antibiotic ointment for a while and it slowly got better, then I started masturbating with eucerine lotion and it flared up and got really raw, itchy, and sensitive. In these other posts someone mentioned psoriasis, which I have had on my head and leg since a toddler. I am hoping it is and isn't that. I have a full battery of STD tests coming up which should all pass as negative since I just ended a marriage of 5 years. But the person that mentioned psoriasis said that they haven't found a cure yet. I know ultraviolet treatments are good. I haven't been tanning in 8 years so maybe I should start back up. Anyways, good luck, If I find out more I'll return and post.