Scab on abdomen

[fatimastic]

My Australorp hen has this scab right below her breast bone. I checked my other hens and a few of them also have similar kinds of scabs. Their bare skin is also somewhat flaky. Her skin looked red and irritated, but isn't that because of the exposure to sun?

 

[coach723]

Looks like a breast blister, or the start of one. Similar to bumblefoot, but on the breast. Happens when they sleep in damp, wet, or soiled bedding rather than roosting, or when they rest the keel on the roost while roosting which causes rubbing, pressure and irritation.
Check all feet for signs of bumblefoot, that can cause them to roost incorrectly and cause this. Some heavy birds roost this way as they have trouble roosting properly. Changing the kinds of materials or sizes of roost bars can help, depending on what you are using, or padding roosts (has to be something they can't pick and swallow) can help. This thread shows a severe breast blister and how it's treated: https://www.backyardchickens.com/th...ister-graphic-pictures.1096276/#post-16850510
If it's early enough and it's still superficial and shallow then just soaking, removing all the gunk and applying an antibiotic ointment until it heals may be enough. The underlying reason it formed needs to be addressed to prevent it from happening again.

 

[fatimastic]

Looks like a breast blister, or the start of one. Similar to bumblefoot, but on the breast. Happens when they sleep in damp, wet, or soiled bedding rather than roosting, or when they rest the keel on the roost while roosting which causes rubbing, pressure and irritation.
Check all feet for signs of bumblefoot, that can cause them to roost incorrectly and cause this. Some heavy birds roost this way as they have trouble roosting properly. Changing the kinds of materials or sizes of roost bars can help, depending on what you are using, or padding roosts (has to be something they can't pick and swallow) can help. This thread shows a severe breast blister and how it's treated: https://www.backyardchickens.com/th...ister-graphic-pictures.1096276/#post-16850510
If it's early enough and it's still superficial and shallow then just soaking, removing all the gunk and applying an antibiotic ointment until it heals may be enough. The underlying reason it formed needs to be addressed to prevent it from happening again.

They had bumblefoot, we treated them for it. There is no visible scab on her feet but her toes still look a bit deformed. They are soft though.

This is what their roosting area looks like. Sorry for the mess, we change the sheet once every 2-3 days.

How should I go about their blisters?

 

[coach723]

At the end of my post I explained how I would treat, if it's deeper (as shown in the link I gave above) then I would treat as in that link.
I see a bit of swelling and maybe some early pododermatitis on the foot. That can have multiple causes most common being the ground or bedding they are walking on, particularly if it's heavily soiled (droppings accumulation) or wet.
I would give the roosts a good scrubbing to reduce bacteria. If you can seal them with paint that may help. Mine are painted and I scrape and wipe down with vinegar every morning, just my routine. Here is an article on contributing factors to pododermatitis:
https://www.thepoultrysite.com/articles/what-causes-foot-dermatitis-in-poultry