Can whole milk burn a baby's bottom- bad diaper rash?

Just gave my dd some whole milk. We started out 4 ounces formula/ 2 ounces whole milk, and gradually changed the ratio in her bottle to now 2 ounces formula and 4 ounces whole milk.
But over the last two days her bottom has gotten a very bad diaper rash. She screams and screams because her bottom's raw.
I don't need advice on treating the rash. I know how to handle that part. What I'm wondering is if introducing milk can make this happen??? The only other new food she's had recently is maple syrup.
Anyone else experience this? Did is get better?
(I've stopped giving her whole milk for now.)