What do you suggest if my child has a petechiael rash on her chest and back. the doctor said her blood work was ok. what could be the cause of the petechiael rash?

Enterovirus?: This time of year certain enteroviral infections go around and they can cause petechiae (essentially enterovirus is just a common virus that most kids get)The CBC should rule out "bad stuff" like leukemia or other blood disorders & serious infections.Trauma can also cause a petechiae as well. Of course, I really don't know your child's history. Sounds like your ped is doing everything as I would)