I had a few that looked horrid during their molt last year, and it was during the start of the cold spell, one looked like an oven ready bird with blood where her tail feathers were, I kept checking on here expecting her to be found dead, BUT, all her feathers returned and she was fine again.
My Drake used to part the feathers on their backs (any port in a storm) some chickens pluck themselves too, They may be a bit of bullying going on too!!!!! Fingers crossed and they will feather up again nicely!!