You need to see a Dermatologist to find out what you have going on with your skin. I had something that took the melanin out of my skin so I couldn't tan. It was a skin fungus that everyone has but in some people it reacts to moisture and sun and it take the pigment out of your skin and it can get red and itch. I had to take Nizoral to kill it off but it is no guarantee of permanent elimination of the problem it can come back at any time. This you can only get as a prescription but there is a cheaper generic to it.
I have used a shampoo that has 1% Nizoral in it and that appeared to help I used it as a soap so to speak and let it sit on the infected area for a few minutes then rinsed it off. This was a suggestion by my doctor to try out as an alternative to the pills.