Basically what i think is we havent got any connective tissue either from damaging it from picking at the lips till raw or some say they came out the shower and rubbed off the residue on their lips. So what builds connective tissue is collagen. Our lips crust because they are protecting the dermis until we repair the dermis it will continue to crust. So vitamin C and L-Lysine promote collagen growth so that explains how we are reacting to it. I've researched :).