Thank you for your question.
I am Dr. Su S. and I will try my best to help you.
I am sorry for her illness.
I would advise to take her to hospital.
Steroid would cause improvement.
Instead she is feeling worse.
An infection can also cause rash.
Meanwhile, you can give her zyrtec.
It would help in allergy.
Please try to keep her hydrated.
I hope this information will be helpful.
If you have any query, please feel free to ask.
If you are happy with my answer please click on the Excellent/Good rating.
Wish her healthy life.