Raised red patches on shoulders

[RR Chick]

Hi there,
Does anyone know what this might be?...One of my Asa Brown's has two almost identical about 1" raised red patches on the shoulders where the wing feathers intersect with the back. No feathers in the spots and it's rounded she has had it for quite some time. It looks like maybe another girl is getting it too as the feathers are thin in that area and I can see red under it. Does this sound like a fungal thing or a bug thing? No open wound. At first I thought it was bullying from the other girls but it's symmetrical.They're are about 2 years old. Thanks for the help. Otherwise she is fine.

 

[Tesumph]

Do you have a rooster? Sounds like wear and tear from being mounted.
A picture would help.

 

[Eggcessive]

Does it resemble this? Dull your rooster’s spurs (if you have one) with a dremel or file, or tim them with dog nail clippers. Then you may want to make a hen saddle or apron here:
https://timbercreekfarmer.com/how-to-make-a-hen-saddle-or-apron/