Dry lips without apparent cause

Patient: Two months ago, I noticed that my lips started peeling pretty badly. They would shed a new layer of skin everyday, sometimes twice or thrice a day. I had been applying the same lip balm daily for several years, alongside with various lipsticks or lip glosses.When my lips started cracking badly because I skipped the lip balm, thinking that it had caused the dryness, I saw a doctor and he thought that it could be herpes even though there were no blisters and there was no pain (except from the cracks). I followed his instructions, applied the cream twice or thrice daily, but my lips were still insanely dry after 3 weeks whenever I didn’t apply the cream.Now I apply a lip balm twice daily, but it bothers me that my lips are so dry that they appear white, whenever I don’t apply anything. I live in a tropical climate, skip the makeup, drink 4-5 litres of water a day, take a daily multivitamin and never even lick my lips – and the problem still persists. I know it sounds like a superficial problem but I really am very worried about this. It’s driving me mad. Could you suggest a remedy please?

Symptoms: Very dry lips