scaly neck

[Lynnmj]

I just noticed one of my barred rock has some feathers missing on her neck. When I looked closer her skin has a scaly look to it, a little red but not too bad.
Anyone know cause or treatment? She is laying & acting normal.

 

[Isadora]

Would you upload a photo of her neck?
Do you have a rooster? Often feathers get pulled out during the mating.

 

[Lynnmj]

No roosters. I also notice when I went to take her picture that 2 other have red butts & missing feathers. Only have them 10 months so I'm new at this. any help would be appreciated.