About 10 days ago I had my 8 week old Buff Brahma pullet henpecked so badly on her back that she had a patch of skin "missing" that was nearly half the size of my hand. I initially wrote her off as a goner, but decided to put neosporin on it, then proceeded to stitch her back together with cotton thread. 35 stitches or so later I put her in the brooding box by herself and put her on "broiler Booster" vitamin water from Mcmurray, and gave her the 20% chick ration.
To my absolute shock, she is doing very well. Aside from pulling about 5 of the stitches out, she handled it rather well. The skin was streached pretty good to cover the wound, but she appears fine, and her feathers are starting to come back.
I posted the incident here as well, and someone mentioned to me that the skin would grow back even without stitches, and that I may have done more harm than good! Her chicken had more skin missing than mine and it survived as well.
I don't have advice for you, only encouragement. You will have to make the best decision for your situation. Oh yeah, and I prayed for the chicken too... My 4 year old son provided that motivation. I am sure it helped, cause it wasn't me!
Dr. Phrankenstein (not a real doctor!)