IF this is indeed a diaper rash, i agree 100% with the 1st response! AQUAPHOR!!! i would suggest it to anyone and everyone. my mother used it on us, and i use it on my daughter (and it can be used for many things other then just diaper rash!). my daughter's 2nd set of teeth that came in were 4 at once just like your child, and she also got horrible diaper rash, even some blisters, and the aquaphor worked. after about 2 maybe 3 days of aquaphor (and some airing out, just like you do) it was almost completely gone, and didn't bother her at all! JUST GOB IT ON until it seems she's more comfortable. but i would also check with her pediatrician. it could be from detergent, or fabric softner (my daughter got lil bumps all over her body until i decided to keep it down to just liquid, and no fabric sheets). but it may also be a yeast infection, and if it is, you want to get her cream as soon as possible to get rid of it. i've had an external yeast infection before (after surgery) and it was extremely painful. it took a few days of the cream to go away. so i'd say just gob on the aquaphor until the dr. can see her! good luck, and let us know how she's doing!