Coronet band injury?

[Yazmin11]

has anyone ever had one of these before and if so what have you done with it?
My boy has what looks like a bruise but the coronet band of the hoof is swollen as well, what should I do with this?

 

[Hanniimakii]

Have you got a picture? My boy has just been diagnosed with corinitis. Started with coronet band looking a bit inflamed and crusty then started to crumble away.