Someone wrote a post about how his lips felt better with the application of lipids so he thought we might have a lipid deficiency. This might explain it:
"During the day you want a balm that contains a rich emollient like shea or mango butter--they're loaded with fatty acids and lipids that help repair skin--and reapply it often."
"Your instinct may be to buff off the flakes, but don't: This can leave the skin raw and allow bacteria in. Instead, focus on hydration. By keeping the skin nourished and protected, it'll repair itself quickly and stay soft.
To soothe and prevent chapped lips, try doubling up on products. During the day you want a balm that contains a rich emollient like shea or mango butter. Then, before bed, slather on a thick ointment that contains petrolatum, lanolin, or mineral oil to seal in moisture."