I wear boys shoes alllll the time!  I always buy size 4.  Boys DC shoes run a little smaller.  I've even compared them to a pair of size 6 girls that should be the same size, and you can see a huge difference in size.  I would just buy a 4.5 next time.  Also the white mesh part in the toungue gets very dirty very fast, and is almost impossible to keep clean/white.  I try to stay away from white DC's all together.