Any thoughts appreciated

[Kcat369]

My rooster has had these black spots on his comb since the middle of winter. I assumed that it was frostbite but wasn’t sure, I ended up isolating him he in his own coop. It seems to have been getting better but now it is getting worse rapidly. Any thoughts on what this could be? Or how to treat test?

 

[Wyorp Rock]

Likely he's rubbing the comb on the wire if he's isolated from the hens.
Most look like scabs to me. You can try pine tar to see if that helps them heal.
With hens, they likely will pick at the scabs, mine would.