CCUK
Free Flying
If it is fowl pox there's not alot you can do. This is interesting reading.
https://www.backyardchickencoops.com.au/blogs/learning-centre/taking-the-pain-out-of-fowl-pox
https://www.backyardchickencoops.com.au/blogs/learning-centre/taking-the-pain-out-of-fowl-pox