Hello doc .my daughter is turning 6 .her skin at some area of body getting black like at elbow and at neck.pls suggest how to cure

A. Take two tablespoons of besan (gram flour), half teaspoon lemon juice, a dash of turmeric, and some rose water (or milk). Mix all of them and form a medium consistency paste. Apply the mixture on your neck, leave it on for about fifteen minutes, and rinse with water. You can repeat this remedy twice a week.