hmm, not sure, I hope someone else can chime in...
I would check him for mites and such and see if there is a physical reason
he is losing his feathers like that...maybe post a picture, that may help also,
Have you gotten hold of your rooster to look and see if he might have mites or lice? You would need to look way down under the feathers, next to the skin. The vent area is a good place to look, and also under the wings.....
If you see any critters, then buy some Seven Dust, and give him a good dusting. The whole flock may require it. Then you repeat in 14 days, because the eggs will hatch and then you'll need to kill the baby lice/mites before the are mature enough to lay more eggs and repeat the cycle.
Usually the skin is not bright red, so I'm guessing it's a parasite problem.
He's a good looking rooster. If you can't catch him during the day (not sure how tame he is), night time, when they're on the roost in the coop is a good time to look. Mites hide in the coop during the day, then come out at night to feed on the blood of your chickens. Lice will be there all the time.
During the night, chickens sort of go into a super calm state, so they're easy to catch.