My 14 yo daughter has developed dark patches accompanied with hardening under skin and redness like chaffing? It itches alot. I am currently using Schreiner's herbal solution. Any thing else I should try? Do you have any idea what I am dealing with? Seems to help we have only been using two days in a row. Itching is minimal now except for when active/sweating redness/chaffing occurs. Only in one pit. I have ruled out sensitivity to soap, detergent or deoderant.