question: HI, I had a fever for 4 days straight and felt so weak, didn't get out of bed.  Then I developed a sore throat.  I went to the doctor and tested negative for strep and the flu.  But after blood work, my white blood count was a little elevated, so i was put on tamiflu and augmentin.   I have a horrible cough I can't get rid of with phlegm.  Now, I have a rash on my chest and the back of my neck.  What would cause this rash?