There is something special about lip anatomy that makes it vulnerable to dryness. It possibly contributes to the start of inflammation of the lips (cheilitis).
This blog post illustrates the difference in the anatomy of normal skin vs lips very well. As you can see it below, the outermost layer of our skin is called the stratum corneum. For areas other than your lips, this stratum corneum usually consists of more than 10 layers of stratum corneum cells, while the lips only have 3 to 5 layers of such cells. This much fewer layer of cells makes the lips prone to the external environment be it cold weather, UV light, or irritants. Also, there are no sweat glands for the lips. Natural sweat glands can keep the skin well hydrated and reduce increased water loss from the skin.
With this knowledge of the difference in the anatomy of our lips in mind. We can appreciate how our lips are so delicate. Once we developed exfoliating cheilitis, that’s postulated possibly due to the lips’ barrier being defective, possible cascades may happen like inflammation and secondary infections.
One of the core treatment for exfoliative cheilitis will be frequent application of moisturizers. You can refer to this post on the lip balms I have been using.