What Is The Rash On The Back Followed By Fever And Cough?

Hi, my 13 month old daughter has a rash on her back which appeared about 2 days ago. I took her to the doctors this morning and they give her eczma cream but has all of a sudden got a temperature n looks unwell. She got up with a cough this morning aswel which has got worse through out the day but she's been fine otherwise until half an hour ago. She was only just ill a week and half ago. Is it anything to worry about? Thank you for your time.