Yellow crust on my chickens comb, cheeks and legs. Help

[A-TeamMama]

I have serched this site and can't seem to find a match to what is happening here with my chickens. I have Daisy, a one year old speckled Sussex who began showing signs of illness about a month ago. She stopped being social and just hid in the coop. I couldn't find anything really wrong with her so i brought her into the house and have quarantined her in my dinning room in a large dog kennel and on nice days let her have the enclosed back deck. Daisy is not getting better. She is so thin her breast and hip bones are all i feel when handling her. She drinks and eats, no eggs at all are produced. She is sad. I bathed her shortly after bringing her in and noticed black specks on her comb. I figured she has fowl pox. Its not severe but she isnt improving. I noticed her poop is runny and stinky. I clipped her feathers by her vent and bathed her recently, but no improvement. A few days ago my two year old EE named Maple was limping. Today I realized it was a leg covered in a crusty yellow flakey goop. Also her comb and cheeks have crusty yellow something on them. I then checked my other 8 chickend and another two year old had black spots on her comb, but no crust. Please help

 

[A-TeamMama]

this is maple, by two year old with yellow crust

 

[A-TeamMama]

this is sunday, my chicken with no crust or drainage but black specks, ir pox.

this is Maples leg that shes been limping on, it has the same yellow crusty flaky scales. I. Hope someone can help. I need advice, food, nutrition,antibiotics? Antifungal?

 

[Beatrice&Maple]

I don't know about the foot, but the comb looks a bit like fowl pox.