Based on your information, raventrouble, I have the following suggestions.
Believe it or not, some doctor prescribed medications cause dry lips.
I was on one medication a number of years ago that made my lips so
dry that the skin on my lips was actually peeling off. I told my doctor at
the time that this was happening. He put me on another medication.
He actually asked me if I found this bothersome ? I repeated, the skin
on my lips is peeling off. No, I can't live with this. Find me another
medication where this is not a side effect. Needless to say, I also
found a new doctor. This is one scenario. I was also told to drink more
water which I am trying to do now. I find using a chap stick helpful,
but all kidding aside, it may be that you're not drinking enough water.
I hope these suggestions help.
Vitamin deficiencies, allergies, antihistamines or other medication side effects are some common reasons.