White/ brown scab on Rooster comb

[chookhead]

Hi,
I currently have a mixed Australorp rooster who has a wonderfully large red comb. But for some reason near the base at the back of his head there is an odd scab forming. It was initially white then it changed to brown and grew. The brown is surrounded by pale and seemingly flakey white. I cannot get a photo because I cannot catch him during the day. I will try to get one ASAP and post it here. He is happy and healthy, is eating, pooping, crowing, and mating so it does not seem serious. Just ugly to look at and probably uncomfortable for him.
Thanks in advance

 

[Eggcessive]

Could he have a peck wound or have injured his comb on some fencing? The picture may help.