Red swollen backs, help

[Chickassan]

They're growing new feathers, they've been molting.
See how brand new ones are coming in verses old ones just being broken off?
Are they all pretty much the same age? That looks like mini molt level feather replacement.

 

[Wyorp Rock]

Hello,
i have 15 hens and one rooster and the rooster and about five or six of the hens have something going on. Their back, next to the tail is red and puffy and when i touch it they freak out because it hurts. there are no feathers there either but nothing else is irritated and they keep itching/cleaning it. i noticed it about a week ago and thought molt but its red and puffy and they haven't lost any other feathers. laying and behavior is normal in all of them. i checked for lice and found nothing. i put DE in their coop regularly so it cant be blood mites. I also give them DE every other week in their food. The only thing that we haven't done is dewormed them but their poop is normal. Whats going on? What should i do?

Are they constantly picking at those places or just preening?

 

[Farm life101]

Are they constantly picking at those places or just preening?

ive only seen them preening but i dont watch them to much.

 

[Farm life101]

They're growing new feathers, they've been molting.
See how brand new ones are coming in verses old ones just being broken off?
Are they all pretty much the same age? That looks like mini molt level feather replacement.

there all different ages. The ones who have the issue, theres 3, 1 year olds 2, 3 year old and the rooster is 4 i believe. i thought it was molt but it red and puffy and there loosing no other feathers.

 

[Wyorp Rock]

ive only seen them preening but i dont watch them to much.

there all different ages. The ones who have the issue, theres 3, 1 year olds 2, 3 year old and the rooster is 4 i believe. i thought it was molt but it red and puffy and there loosing no other feathers.

Being red, painful and puffy, I would be inclined to treat them for Depluming (Feather) mites.
Get some Ivermectin Pour On and dose them at 0.09 ml per pound of weight. Repeat in 10-14 days. To apply Pour On, measure out the proper dosage with a needle-less syringe, then put the drops at the base of the neck along the spine, the liquid needs to come into contact with the skin.

 

[welasharon]

Is this near the oil gland?