We don't have that problem...and I have a fatty. So I would be wondering if it is yeast or eczema too. Just since it is so irritated. I would try some coconut oil on them. Or some California baby cream to see if it helps. Those are both good for eczema. If it doesn't look better in a couple days, I would check with the doc. Just to be sure it is not yeast
But enjoy those little rolls. Kieran just started moving around seriously and I know I will be saying goodbye to his little rolls soon enough