HI, My 14 Month Old Has A Bad Rash That

HI, My 14 month old has a bad rash that started on her face. It then spread to her arms and legs. All the while she had a runny nose and a low grade fever, about 99 degrees. Five days after the rash started she got very ill with diarrhea, cold like symptoms, vomiting and the rash progressed to the under nearth of her arms and legs. She has nothing on her truck, front or back. I took her to the doctor and she they ruled out bacterial infection. Any ideas? Thank you