low blood platelet count pinpoint rash

i do not know what is wrong with my daughter she is 11 years old, perfectly healthy
she got ant bites, next day they were infected, and we noticed that all around them was a rash and pin point purple to red blood spots, they were flat, but very itchy, she scratch them and they got bigger or a tiny bit swollen,   Then the next day it is like her whole body exploded with these little tiny pin point spots, feet to her hips...   doctor said antibiotics for infection, blood test to see her platelet count.. it was low he said. and said that it could be a viral that caused it.
Now my daughter has a horrible headache and her abdomen on top right side in front hurts alot and to her middle.  Her temp is normal..  
I don't know if she is just having alot of things going on, or they are all connected.  doctor said in a couple of weeks rash should be gone.  and i noticed to day, they are starting to look a little brown looking. so maybe her body is absorbing them.     can anyone else give me any advice and what to look out for? I just wish her headache would go away, i gave her some tylenol, but it doesn't seem to cut it.  I know ibuprophrin and asprin is not good cause they cause bleeding, so i don't use that, as doctor explained it is not good for the platelet count.     Help please...