That is a great question and one that is best answered by your child's pediatrician
. There are several causes for what you have described and although it should not cause alarm, it is important that a doctor
evaluate your son or daughter to make sure that this isn't something serious. One potential for this odor could be lack of personal hygiene which is not uncommon in this age group. Does your child take regular baths and practice good hygiene? If it appears that your child has signs of puberty such as underarm hair or genital hair, then there is a potential that your child is experiencing precocious puberty and it is advisable that he or she is evaluated by a doctor as this can sometimes be related to an imbalance in hormones that regulate puberty. Age 7 is too young to begin to develop puberty so if this is occurring, then your doctor will likely want to figure out what is the cause for this. Finally, with regards to the odor, while you wait to be seen by the doctor, there are several non-deodorant methods to improve the underarm smells such as baby powder, baking soda, and increasing the number of showers or baths per day but make sure they are evaluated by a doctor.