What Causes Recurring Dry Spots In An Infant?

my daughter is about six months old and she has always had dry spots on her face by her ears and now she is getting a rash on her stomach and back which keeps getting worse it is dry spots and some little bumps on some of them! i put aquaphor on it daily and it goes away a little bit but comes right back! i also started her on new foods but it is only on her stomach and back! what could it be?