Reaction to diapers?

Abby

Has anyone's little one had a reaction to a brand of diapers after they have worn them for a little bit? We started using luvs last week because we went up a size and that's what I had. Well the first pack she did fine with, but I opened a new pack last night and now she has a rash all over where her diaper is. It's just little bumps everywhere not like a chemical burn or anything. Has this happened to anyone else?! The first pack was fine.