Since you are starting to feel strongly that this is Psoriasis (and Im with you), you should start treating it as so. There are exterior ways to treat psoriasis, not just thickening your intestinal wall (however you do that).
Since your not doing this leave it alone method anymore you should consider using some topical ointments to treat psoriasis, since I havent read about anyone who has on here. I can discuss some of the topicals that a dermatologist suggested to me, and she is an Inflammatory Skin Disease Specialist, so shes not just some hack. Im also seeing a Psoriasis specialist on Monday, so I will see what he thinks. Let me know if you are interested in this and we can discuss it. I think its a good idea since your not opposed to using stuff on your lips.