In rare cases, perspiration with an odor can be a sign of early puberty. If your daughter has any breast development, or any pubic hair or hair under her arms, you should make an appointment to see a doctor right away.

Most likely, this is nothing to be worried about. I have seen this in many patients. Washing her underarms with antibacterial soap may help. (The smell is related to bacteria in the skin.)

A couple of my patients were helped by using an antibiotic lotion (one usually prescribed for acne). You can talk to your doctor about this.

Deodorant isn't usually necessary, but it is an option. Look for one that is only deodorant. You don't want one that is a deodorant and an antiperspirant. The deodorant should also be as hypoallergenic and natural as possible.

If the problem continues, call your doctor for advice.