hens preening to much?

[BantamPhantom21]

4 hens just getting over lice infestation and scaley leg mights, I have 2 that wear hen savers cause the boss plucked the back. And those two have been preening there selves alot lately. Under them on the bellys is baldish. Just, gone. And the one whilos is worst does it in the nestbox. Cause there skin be itchy for stuff used to kill lice??