What causes dry and cracked upper lips?

As summer passes, the weather in autumn is bound to be drier. This will make our lips dry and cracked, which is very uncomfortable. So why do lips become chapped and dry? What is going on?

1. First of all, the lips are mucous membranes, without sweat glands and no oil secretion function, so in the dry season, the lips will easily become dry. At this time, many people will lick or bite their lips with their tongue. Although the saliva temporarily moistens the lips, it will quickly evaporate and take away the moisture that is already scarce in the lips. As a result, the lips become drier and the more you lick them, the drier they become, which creates a vicious cycle of chapped and peeling lips.

2. In addition, saliva contains protein substances such as amylase. After the water evaporates, the amylase sticks to the lips and causes the contraction of the deep connective tissue and wrinkling of the lip mucosa, which makes the lips dryer and even causes infection and swelling, causing pain. The amylase protein remains on the lips and forms a scab together with the cells that fall off the lips. Since the tissue under the scab is incomplete, if it is torn off forcibly, it will cause more local exudation, thus forming more scabs.