Hen has lost feathers on belly and skin is quite red

[Meweber]

Hi- I have a Rhode Island Red, about 16 months old (we have 15 other chickens); my son informed me today that she has lost feathers on her underside, mostly the chest and belly area, mainly and not near the vent. The bare skin is quite red and looks inflamed. Near the end of where the feathers are gone, I can see there are short little bits of feathers at the edge of the bare spot, then normal feathers beyond that. I didn't see any bugs/mites/etc on her, but I know they can be hard to spot, too. She seems to be behaving normally as far as we can tell. I don't believe any others in the flock are affected like this, but we'll check them all out tomorrow to confirm that. Wondering what we might be dealing with here. I don't believe she is molting, as there are no other feathers missing. I will attach some pictures to show what her underside looks like. Our flock does limited free ranging, and has not been out much lately. As far as I know, all the chickens roost on the roosting bars (2x4's) in the coop, but I wil check to make sure they are all roosting on the bar tonight to know for sure. I haven't known any to do other than that unless they've gone broody, but this one is not broody.View attachment 3173900View attachment 3173901View attachment 3173902View attachment 3173903

Hi, I know this is a very old post, but curious how your chicken was/is doing? I have one that looks exactly the same and has for weeks and I have no idea what’s it’s from. She’s otherwise acting completely normal. Thanks