My daughter has dry pale and painful skin around her mouth. What is wrong with her?

Probably licking. I know, she says she isn't running her tongue around her mouth, but she probably is. Kids tend to lick dry skin around the mouth, and the saliva makes it drier, which makes them lick more, and so on. Other possibilities include an allergy to something she's eating or applying to her skin. Some doctors believe the Fluoride in toothpaste can cause this, but I am not one of them.