What can cause lips to get darker, other than smoking?

Over the last few months, my lips would feel as if they were scrubbed, then they would appear red..and later turn darker...then after a week they go back to normal. I don鈥檛 know if its an allergic reaction to something or a more serious condition. I always were chapstick, I consider myself addicted to chapstick. I don鈥檛 smoke anything, and never have.What can cause lips to get darker, other than smoking?
it does sound like some sort of allergic reaction, it could also be a lack of adequate hydration too. The body needs two liters of water daily to function at maximum efficiency.What can cause lips to get darker, other than smoking?
It could be a number things, alcohol, allergic reaction to something you are eating, drinking, or some type of chemical imbalance, blood circulation issues, or blood problems, I suggest seing a doctor and have your self checked, because sometimes symptoms are warnings of something else.