What is this?!

I have not done anything out of the ordinary with my son. His detergent has never changed from dreft. Same lotions since birth and same formula since birth. And suddenly he is getting this rash here and there. I am not sure what is causing it and I can't get it to go away. It just will do it on its own after multiple hours and the. Come back within a day or two... Any ideas? I did put some intesive repair lotion on him the past few days and switched his bath soap to cetaphil to help but no changes yet and its not on his legs at all. His skin also always has felt super rough for weeks now and I try to keep it hydrated all the time.. Help!