Scaly / crusty comb

[dandefrancis]

This is the only one of my six birds that has this on his comb. He’s acting fine, vent and legs are clean.
Any advice on what this is and how to treat would be great.

 

[Eggcessive]

It could be fowl pox, a virus from mosquitoes. It lasts about 3 weeks, and most chickens recover just fine. I have never seen the scabs in such a pattern before. In the article below, you can look at other pictures of fowl pox.
https://the-chicken-chick.com/fowl-pox-prevention-treatmen/