that looks like foul pox. it can be really dangerous in young poults. all mine are dealing with it and are getting "helmets" of big scabs over their face. i suggest you rub triple antibiotic ointment on the scabs 2+ times a day. i just started today because i had gotten advice on how to treat them. they're already looking a little better, but not by much, just some of the scabs are coming off. but apparently that's the way to make the huge ones go down. i have to help most of mine eat and drink multiple times a day because they can't see. i thought we only had dry fowl pox in the flock but apparently there's wet fowl pox too. it killed one of my poults and i just noticed it in one of my worst ones when I was treating them. it is not good at all. be sure to check that yours doesn't get the things in its mouth because it's bad. i don't know how that ones treated, tho
(i attached an image of mine that didn't make it)