I Have A A 11 Month Old Granddaughter That Has

I have a a 11 month old granddaughter that has a serious rash feels leathery,with bumps .I have removed my 6 year old grandson because of same type of abrasion rash on his rear end and he told me that the boy basically sexually abused him.How do you diagnose it and as Im not custodial gaurdian of her what can I do