Unexplained Rash then low grade fever

My 3 year old developed a rash that covered his entire body. Felt like sand paper but not really dark in color. The next day he developed a fever of 100.5 that lated about tow days. The fever  went away and the oink rash left but the rough skin that feels like sandpaper is still all over his body and he has begun to itch. It is not peeling. He is digging at his ears and keeps rubbing his head. I took him to his doctor and she said it was just viral. They tested for strep and it was negative. We are now 8 days into it and he is still itching and his skin is very rough. No idea what this could be.