Everyone thinks its either internal or external - maybe it is both? Or maybe different things start it? I've read that a lot of AIDS patients get exfoliative chelitis - to me that means it has something to do with the immune system. Then maybe the peeling of the lips makes it continue. I think my sons was caused by Acne medication upsetting the immune system. My son is doing everything right now - candida diet, supplements, detoxes and also just started not peeling his lips. Hopefully it will all work together - I think a good diet has to help even when you are just leaving the lips alone. I just wish we could find a way to speed up the healing - we are looking at light therapy - which helps heal skin supposedly - just tired of spending so much money and nothing seems to help!