It is possible that a diet high in sugar caused yeast overgrowth. It is also possible that yeast overgrowth caused my celiac disease. I think an infection- whether bacterial or fungal- makes the lips peel. And, these organisms enter cracked or raw skin. It is the condition that causes this cracked or raw skin, which should be the focus. In my case, celiac disease seemed to cause chapped lips as other food intolerances. A strict diet was challenging at first, but it has become a way of life.