Suggest Treatment For Rashes On Legs Of A Child

my daughter 14 years old. She has a rash between her legs and occasionally she breaks out into a more severe hive like rash just between her legs and a couple quarter size marks on her arm. She keeps getting the chills but has no fever. She also get headaches. She just had an appointment for her issues and the bloodwork came back that her kidneys are a little elevated. Just trying to get someinsight of what it might be while waiting for her appointment next week. When she was 12-13 years old she was getting a UTI quite often but tells me her urination is fine. no belly pains, other than when she has her menstrual cycle. thanks for any insight