My Rhode Island Red has missing feathers and a sore that will not heal. Does bleed on occasion. I’ve tried a salve for chicken injuries. Not sure what to do.
Your hen appears to be molting, so the uropygial gland/oil gland becomes more visible and the skin gets irritated because of the pin feathers growing and pinching.
You can try a warm compress with sage tea to soothe the irritation and spray the area with triple antibiotic or BluKote spray to prevent the others from pecking.