6 Year Old, Fever, Vomiting, Fatigue, Rashes On Body. Cure For Symptoms?

hi, my six yr old son had a fever on sunday with vomiting and fatigue. On Monday he had a low grade temp but was active and a slight runny nose. Today he had no fever and felt fine but now he has a rash on his chest, back, arms, legs, groin area even the tops of his feet. The rash is pinpoint dots under the skin. He says it does not itch. I looked in his mouth and he has red pinpoint spots on the top of his mouth but says his throat is not sore. He has never had strep before nore has his father or I. Any help would be appreciated. Thanks in advance