Hi. My horse recently got a sunburn and now it has gotten all...i guess you could say crusty, almost like a scab, and i am assuming it is in the late stages, it is hard to explain with out pics, but it can be rubbed off easily if i were to try. We are treating it but does anyone here know who long it takes to fully dissapear or stop being so crusty?? thanks. its all around his nose and up until about the bottom of the flymask.