Dr. Greene’s Answer:
If you look at a classroom of 4th grade children or 8th grade children, you will quickly notice that children develop at very different rates. The differences depend partly on genetics and partly on the environment (obesity, for instance, sometimes triggers earlier puberty).
Girls typically begin to have underarm odor and perspiration anytime after the 8th birthday and boys anytime after they turn 9. If these changes happen earlier, or haven’t happened by 13 in girls or 14 in boys, it’s wise to check-in with their pediatrician to be sure that everything is on track.