Welcome to HealthcareMagic. Normally the sweat is odorless but due to the action of Bacteria it produces an unpleasant smell. It can be due to personal hygiene, fungal infections, over weight, eating spicy foods or medical conditions like diabetes
Keep the area dry by using a talcum powder. Have a healthy and nutritious diet and maintain good personal hygiene. Add few drops of savlon
to the water you use for bathing and use antiperspirant deo. If the symptoms persist then fungal infection has to be ruled out.
Hope it helps you. Regards.