I received an email from a mother who asked if her 5 year old son, an avid athlete, could wear deodorant? It seems that his arm pits "smell like a grown man". I have actually been asked this on occasion in my office and I have even noticed body odor (BO) during exams on some 5-8 year olds.
Most children start to "stink" as they begin to enter puberty, but there are occasional children that for unknown reasons, develop BO without any signs of puberty. If it seems that your child is entering puberty at an early age, you do need to talk to your doctor. If your child happens to be one of those kids who are just odiferous, there are several things that you can do.
Number one, make sure that your child is bathing/showering everyday, and that they wash their armpits well. Some little boys (and I bet a few girls) just pop in and out of the shower without touching soap on most of their bodies. (I used to smell my boys hair when they came out of the shower, sometimes still smelled sweaty, no soap!).
If daily bathing does not do the trick, it may be time to use a deodorant, which just masks the smell. This often works for younger kids who are really stinky rather than sweaty. An anti-perspirant actually stops and dries up perspiration and may not be needed until an older age.
There are numerous deodorant products available, some of which are natural as well. Head to the store and read labels to decide which one you prefer.