What Is The Cause Of A White Area On The Glans?

Hi Doctor I am 28 years old. I have noticed a small white kind of patched area on my glans. I felt itchy on my foreskin and the glan area. After i washed it, the patch was gone but the area underneath the patch is bit reddish than before. And I now can see some more white layer forming around some of the areas over the glans. Can you please advice what might be the root cause for this and what action to be taken.