14 yo son w 40+ spots on his torso. maybe chicken pox but no blisters. he says the red spots started 3-4 days ago, but i didn't see until today. the spots are not visible w/ clothing. no itch, no cold like symptoms. says he had a headache a week?

Hard to assess: Most rashes require direct observation for proper labeling. CPX is a pattern illness, with spots starting as small bumps that enlarge into BB sized water filled blisters within hours. They then break/crust & dry over the 1st day. They come out in crops & usually start around the neck/face & progress to the trunk & extremities. Your description does not suggest CPX, but an exam could say for sure.