We had this. We even changed the name to "bruling" because he'd do it on purpose by burbling and buzzing his lips. He also let milk run down the side of his face into those little neck rolls. eeeeew
When used A&D (the cure for nearly everything, apparently) it would take care of it.
Also...don't know if it applies but we bathed him at least once or twice a day, and I used babywipes on him after nursing. He was a water baby though....loved loved loved the water.
I'd be careful of the cornstarch. They don't put real talcum in talcum powder anymore...they use cornstarch...and it can cause/significantly contribute to yeast infections. We KNEW this, especially in little girls (we had a boy), but we didn't realize you can get a yeast infection durn near anywhere. Including in little neck or thigh rollies. Anywhere with moisture and heat.
And thank you again, A&D.