Skin infection not healing + spreading. Disease?

[whatheflock]

Our 4-year old Rhode Island Red has had a head injury for the past month or so. Since then, it has spread to the other side of her head and down her neck. We haven't seen any pecking order conflicts, and none of the other birds have it.
No treatment so far, but we're looking into getting a BANIXX CHIXX spray.
Is it just an injury? And is there anything else we can do to help her recover?

 

[Eggcessive]

She could be molting by the evidence of the bluish pin feathers, and they are possibly being pecked out by the chickens. Gentian violet or BluKote a staining blue-violet antiseptic, can be used to hide the bare red skin. Or you could use anti peck cream, vaseline, or Nustock cream.