viral?hives&diarrhea

I have a 4 1/2 year old grandchild who has had severe diarrhea for the past three days. She is also breaking out in hives when she gets excited or over heated. Her face might turn bright red but her nose will have a yellowish ring around it. And her face will be swollen. Then it might be her toes and finger-again turn bright red and swollen. Next it might be the left calf. No fever, no other symtoms (symptoms). The doctor told my daughter she suspected a viral infection. I have never heard of hives like this with diarrhea.

[chigirl29]

I know people freak out when they hear the world Herpes, but she may have a strain of it.  I knew a man who contracted it as a child and when he gets overheated, he has similar symptoms.  I would take her to another doctor and/or have some labwork done.