Differences in lip and facial skin

Why should you use lip balm if you already use face cream? Why do lips become chapped, dry, and sensitive so quickly? Why is regular lip care essential?
To understand this, you need to look at a cross-section of the lips. The skin on the lips is only about 0.2 millimeters (three to five cell layers) thick. By comparison, facial skin is about 2 millimeters (16 cell layers) thick. In winter, dry air from heating systems and the cold are the biggest problems. Intense sun exposure can also dry out the skin on the lips. It's important to know that the skin on the lips has no pigment cells and is therefore particularly vulnerable to sunlight. Constant talking and gesturing also puts strain on the skin on the lips. With increasing age, so-called "perioral wrinkles" (expression lines) can even form around the lip contour.