Possible cause of a slightly rough, dry area on inside of lower lip?

[expatrob2712]

I am a mid-20s male who used smokeless tobacco for roughly 7 years. For the past 12 months I have had no tobacco products inside of my lower lip (worded this way due to occasional snus use, which is a non-moist product for the upper lip only) and I have never smoked. I have always maintained my teeth very well outside of the tobacco usage and have never had any oral health issues such as cavities or warning signs of issues.

On the inside lower left of my bottom lip, there has been a slightly rough-to-the-touch area for roughly two weeks. The best way to describe the feeling would be 'leathery'.

This is not on the visible part of my lip (if I were to close my mouth and look in a mirror it is not visible), but rather on the actual inside, opposite my gums halfway down on the inside (teeth-level). If I close my mouth, the top of my bottom teeth rub right on this area.

It is only noticeable with my tongue: I cannot feel any difference in the surface texture when I run my finger over it. It is not noticeably discolored, and has the same color as the rest of my inner-mouth, which I deemed to be normal (it is not flaky, white, gray, inflamed, or bleeding) . If I hold my lip away from my teeth and gently rub off the top layer of moisture, the area becomes matte under a light, as opposed to the surrounding area, which still glistens. The area is roughly 1.2 cm x .5 cm, if that.

It has not spread, from what I have observed, but it has also not lessened. I try to touch it with my tongue as little as possible to avoid exacerbating the problem but now that it "won't go away" I pay more attention to it and sometimes will agitate the area.

There is no pain or swelling, and if it weren't for the fact that it does not seem to be getting any better and my history of smokeless tobacco use in this area of my mouth, I would not be worried at all (I say this to give an idea of the severity - it is not something one looks at and says "go to the doctor!")

I have a dental appointment set for the 22nd. I am wondering about the likelihood that this is a general aggravation of the mucous membranes from for example increased salt intake (drying out of the area) , or possibly something more severe. Of course, this description will not aid in an actual diagnosis, but perhaps it will provide enough information to receive an answer to help me ease my nerves before the 22nd:)