Hi, Thanks for you query.
The commonest cause for itchy bottoms among small kids is worm infestation. This is because they tend to put all sorts of things in their mouth at this age. My advice to you is to give her a course of deworming now and once more after 6 months. Meanwhile insist on proper hand washing with soap and water before and after meals and after going to the bathroom. Discourage nail biting or thumb sucking
if present.Also, use loose cotton panties for her, wash with water after urination and passing stools and keep these areas clean to prevent recurrence and to prevent urinary infection which is common in girl children.
Hope your doubts are cleared.. bye