Suggest Remedy For Itching Due To Scarletina Rash

My 5 year old granddaughter was seen by her pediatrician on Wednesday. She has strep throat and scarletina rash. The doctor perscribed amoxicillin and mupirocin ointment usp, 2%. However, the last 2 nights, she has been extremely restless because she is constantly itching her back, abdomen area, and underarms. Do you have any suggestions for helping calm the itching? She is already complaining with itching, again tonight. Thanks.