Purple comb

[essaylichicks]

Recently, i noticed one of my barred rocks is getting a stiff, hard, purple comb. How can i treat it? what should i give it? what's this called?

 

[Wyorp Rock]

It looks like it may have been pinched or injured somehow and that portion of the comb could be dead. Personally I would leave it be and see if it falls off (self dubs).