Loss of scales on chicken leg?

[Gabrielle]

My chicken lost scaled on her leg, and under it it's completely black. I am worried if they won't grow back, or thias might happen to my whole flock. I have 7 chickens, and this happend to my Easter egger, please help, thank you!

 

[Gabrielle]

It looks like this?

http://i1.squidoocdn.com/resize/squ...6071photo_1266050771chicken-scaly-leg-mites.j