6 week old pullet, now have bald spot on back.

[Magpie121]

Hello y’all I’m new here and new to raising chickens in general so seeking so insight!
I recently transitioned my fully feathered 6 week old Brahmas to their coop. I checked on my girls this evening and I noticed one of them kept messing with her back. I looked at her and she has a patch where all her feathers are gone and the skin is dry and crusty. Otherwise she acts fine. Eating and drink as normal.
I wasn’t sure if this is something that could be stress related or something that needs to be treated.
Any help is appreciated. Thank you

 

[sourland]

If they were fully feathered when they were integrated, the older birds are feather pecking/plucking her.

 

[Magpie121]

If they were fully feathered when they were integrated, the older birds are feather pecking/plucking her.

Will they do that even if they all did fine while in the brooder together? I have some Wyandottes and Starlight Eggers, but they all have been together with my Brahmas since day 1. I never noticed any signs of them picking at each other.