S.W.
Ringworm is a very common fungus that spreads easily and is contagious before it even shows up on a person or an animal. You have no way of knowing if he got it through the daycare, and it could be spread at any daycare. You could just as easily have brought it home from work.
Here is some info about ringworm and the OTC treatments to try first:
http://www.mayoclinic.com/health/ringworm/DS00489
I remember having this as a child, along with my sister. We put cream on the spots for awhile and it went away.