C.B.
First off, and not meant to put you down, but is he being held by anyone with odor? My eldest was always getting complaints from his great-grandmother that he smelled, but it was just that the heat and all the people that held him left their odors on him. Second, baby powder can effectively be used on all of the body. If it continues, scented wipeys. It is most likely that the odor is coming from some source outside sweat glandsand/or B.O., something he is doing that you are not aware of. He could be placing his hands in his mouth and wiping saliva that creates smells, or putting his hands in the other end (which is extremely normal at that age). However, like the fact that some boys lactate for the first few months, sometimes the glands themselves are pre-productive and it should all resolve itself.