S.H.
How old is she?
All I know is, when my kids were younger, and had colds and fever..... after a few days they'd get a "rash."
And it was a viral rash.... the virus or whatever it is, leaving the body etc.
Look up "Viral rash" Google search.
But my kids would get it when they had a cold AND a fever type thing.
The Pediatrician was rarely concerned about it.
A generic type rash, thing.
And it went away in time. After my kids were sick.
Rarely causing any itching or discomfort.
Why not just take her to the doctor and who the Doc the "hives" or take a photo of it.