S.G.
I'd send him. I have 4 children. It's a good idea to teach them that it is important to go to school, even when things aren't perfect. As long as they are not contageous. As they get older, they will be less apt to want to stay home for lesser reasons.
My rule was if you don't have a fever or are not throwing up, and don't have anything that could possibly be contageous, then you go to school. Everyone has their ups and down days. Good for you for looking out for other children. Not a lot of parents do,