How early is to early to have body odor?

Younger than 7: For girls younger than 7 years and for boys younger than 8 having body odor or other signs of puberty may signify early puberty. Schedule a check up with your doctor and have them be evaluated.

Can start very early: Body odor, aka bromhidrosis, is caused by several components of the skin flora, most commonly corynebacterium, propionibacteria, and staph aureus. If persistent in spite of deodorants, it can usually be managed with a topical antibiotic known as clindamycin. While body odor is more common starting around 9 years of age, it is well-documented in children that are much younger.