What Causes Rash On The Belly After Vomiting?

HELLO I HAVE A 4 YEAR OLD GIRL WHO WAS VOMITING ON FRIDAY UNTILL IT WAS BILE.

i GAVE HER SOME WATER PORRAGE LATER IN THE DAY AND SHE KEPT IT DOWN. I SPOKE TO THE DOCTOR BY PHONE AND THEY SAID IT MY BE A VIRAL TUMMY BUG.

SHE SLEPT AND WOKE UP THE NEXT DAY FEELING FINE AND BACK TO HER ENERGY SELF. SATURDAY WE STAYED WITH FAMILY AND SHE WAS FINE EATING RUNNING AROUND AND HAPPY.

WE CAME HOME TODAY AND WHEN I GOT HER READY FOR BED I NOTICED A RASH ON HER BELLY, BACK OF HER LEFT LEG AND ON HER ARM.

SHE IS STILL OK AND DOES'NT HAVE A HIGH TEMP, SHE HAS NO DIARRIEAH

I CHECKED WITH THE GLASS IT FADES AWAY WHEN I PRESS THE GLASS DOWN.

I HAVE CONTACTED THE DOCTOR AND WAITING FOR THEM TO CALL BACK

PLEASE HELP