I had a hen that had a huge bare spot on her back for several months and at first I thought maybe she was molting. It didn't get worse or better for quite some time so after ruling out parasites and/or illness, I figured that it might be one or some of the other hens picking at her. I didn't have a rooster at the time so it couldn't be from male "attentions", and I didn't rule out the idea that maybe she was picking her own feathers since it was at her tail base. Anyway, long story short, the skin was looking red, sore, a little swollen, and like it needed to be covered so after looking around on the internet, I found these neat little "jackets" called hen saddles and ordered one. I was very pleased to find feathers starting to grow within a week or two of using it and she is now fully feathered. Yay! I ordered mine from hensaver.com, and got the single strap, "Alaska" model (because I live in a cold climate) in the large-for most standard chickens- size and it fit my barred rock hen very well. Don't know if this easy fix will solve your problem or not, but just thought I'd passed it along just in case. Good luck!
