Hello I am new to the site, but not new to raising chickens. I just purchased 10 Black turkans on May 5th, on may 17th I had notice a large bump on the back of ones head. It maybe looked like a bite by something. None of the others had any signs of bites or wounds. Now today the lump/bump is gone, But now her skin looks red irritated and scaly. and almost saggy. Its also traveled down her poor bald neck. It doesn't seem to bother her and she is eating and drinking fine. I haven't noticed anything spreading to the other chicks. So I'm curious what it is and how do I treat it.