J.R.
My daughter had the exact same issues when she was a few months old. I noticed that those patches would pop up after people, mainly my mother-in-law, would hold her. After asking and eliminating things we figured out that my mil used highly scented soaps and lotions. Once I asked her not to use to to see if that was the culprit, we didn't have anymore problems. It was a fairly easy fix.
I do still have to keep her slathered in Eucerin, per my pedi's suggestion. That does the trick for us and we have avoided any other major break outs of it.
Good luck!