What to do with hand foot and month

My 4 year old came down with hand foot and mouth from school, my kiddos haven’t had this before so any tips on how to deal with this. Tomorrow I’ll call his dr and have him seen.. how long do I call him out of school for as I’ll call him out of school to prevent it from spreading but I do have a 2 year old and it’s nearly impossible to keep them separated as they are always messing with each other