lack of feathers on rear and fire-red skin

[FINALLY!FransFlock]

I have a sl wyandotte hen with no feathers on rump now for 5 months, she has also stopped laying and is 3 yrs old. Is this a problem I can do something about or just molting? She is not losing feathers anywhere else and eating good.

 

[Country4ever]

Does she have mites?
If not, I would guess she is being pecked on by the others. I have one that has had a bare bum for many years.
You can try putting bluekote on it. I've tried Vick's vapo rub.......which helps for a little while, but you have to keep applying it. Keep your eyes on the others. It might just be one other chicken that's picking on that one. I have the feeling that the chicken with a bare bummy is low man on the totem pole.