I've had EC for two and a half years now, and my biopsy showed a potential allergic reaction. I had a patch test and tested positive for propylene glycol which is a preservative found in many foods and topicals. It's even found in some topical steroids which might explain why some steroids and lip balms made my lips worse.
I think a lot of people are allergic to some sort of preservative or chemical in processed foods or creams that they dont know about which could cause exfoliative cheilitis. I'm going to go on a diet/skincare free of propylene glycol for 1 month to see ]if my EC lets up and I heal. Hopefully I have found my cure and this is the end to my difficult problem. Godbless to everyone else on this forum and I wish the best for everyone struggling with this debilitating disease.