I haven't bothered to get this diagnosed for a long time, but it's fairly annoying so I guess it might be worth it to try online.
On my lower lip, there are two hard patches of skin that are very dry. I think they may have come around a year ago or so, but I'm really not sure. There's also a smaller patch of the same sort of hard, dry skin on my upper lip as well.
I can always pick off the skin painlessly, unless I accidentally also tear some of the surrounding good skin off as well, which causes bleeding, otherwise, I can tear it off once the "bad" skin fully grows back, and it takes about 2-3 days for it to be hard enough to tear off. If I tear the skin off, the area that the skin used to be at seems kind of raw, and whenever it comes in contact with anything, it stings.
Also there's a pretty noticeable difference between the hard skin patches and the normal skin surrounding the lips, since the hard skin patches have no texture like the normal lips and are very smooth and hard in contrast with normal lip skin that is not perfectly smooth, but when torn off, the lips look perfectly normal.