A.P.
You're correct it can be yeast or it can be pin-worm if he has been around other kids who have it. Pin worm is no big deal, you take 1 pill now and 1 pill in 2 weeks and its gone. Pin worm is characterized by a ring around the anus and a LOT of itching. I am not saying this is what it is but if the ped suggests it...don't freak out...like I said it is no big deal.