Looking for ideas on why my 2yo DS has a red pin point rash all over his bod. I'm not going to call the doc on the weekend since he is mostly feeling fine.

He's had a cold and runny nose for about 2 weeks. Then maybe thursday he started getting these red dots on his diaper region, but creeping up on his stomach. Friday night it was all over his torso. He also had a low fever that night. Around 100. The pin points are pretty much everywhere now. But more pronounced on his belly. They could be fading now. They dont seem that itchy but he was scratching his lower back this morning saying "oowwwww". But its also where the diaper starts so that might be what was itchy.

Any ideas?