I had the same problem with my chin, I was gone for 2 days and came home and noticed a bald spot the size of a dime above his nose. It was flakey and pink, but I never saw him itch or scratch it. I work at Petsmart, where I handle animals with ringworm all the time, so I figured I unknowingly passed it on to him. Took him to the vet, they did the ringworm test and it came out negative. They perscribed him Tresaderm, which helps with flakiness, dryness, and kills any fungus. It started to clear up right away, and his fur is slowing growing back. The vet said maybe it could be from rubbing his nose on the cage, but I'd never seen him do that..
All in all, just take him to the vet and they'll perscribe yours something that will clear it up whether it be ringworm or not.