C.H.
I see someone also suggested tea tree oil. Although I put a few drops into a handful of lotion and then spread it all over. My boys have eczema, and whenever they get a break out I use this one them and it goes away. Tea tree oil also slightly numbs the area so you don't feel the itch as much.
I think it is also allergies. Does he play anywhere around any new carpet? New carpet is what my husband reacted to.