From what I can tell, only one of the hens has this issue going on. It is mostly on her neck, but there is a patch on her head, belly, and on the main part of one wing. The skin is bright red and dry. There are no feathers but there is dark spots where they use to be. I didn’t see any mites crawling around. This is very recent and we were suspecting other hens becoming aggressive to her or possible self-injury? Any ideas on what it is, how to fix it, and advice on how to help her recover is greatly appreciate
That looks very much like feather picking/plucking. Feather loss on back of head may be rooster damage from mating.
You may want to evaluate how much room they have, if you are feeding a food with enough protein, and if they are bored and needing to get outside to free range. Sometimes there are more agressive hens who do this. A simple remedy is to put a little pine tar on the bare spots to help prevent pecking. Nustock Cream is another one that may work. Many TSC and feedstores sell it in the horse supplies.