White oval area on lower lip forms, peels, re-forms, repeats

[Peva]

Pale/Scandinavian-skinned 65 year old mane.  For over a couple of years now, towards one end of my lower lip, there is a white oval-shaped area, varies between about 5 and 10mm on long axis of oval - repeatedly gets more prominent/larger across over a few days, thin layer finally peels, then cycle repeats.  In warmer weather, the whole thing *almost*, but never completely, disappears and the peeling stops or greatly slows down.  Outdoor temperatures below mid-fifties °F greatly aggravates it.  The white area sometimes thickens a good bit and lingers longer before it peels, but that's mostly in the colder weather.  Sure enough, as the weather has turned colder this season, it has formed thicker layers with some soreness.  (There's also a much smaller, 0 to 2mm oval, white spot near the opposite end of my lower lip that appears in cooler weather, but over 50% of the time, *that* spot is barely or not at all visible.)

I get annual full body skin scans by a dermatologist due to 2 benign pre-cancerous melanomas (I hope my terminology is accurate) on my back 15 to 20 years ago - no recurrences, though there are several areas they keep an eye on for changes every year.  Last year during my annual skin exam, I expressed concern for this place on my lip.  They biopsied it (shaved skin) - negative results.  They referred to it as possible pre-cancerous leukoplakia.  (Most articles I read on leukoplakia discuss it in the context of being *inside* the mouth, but I guess it is possible on lips?). I had my GP do blood tests for herpes simplex I and II in my annual physical (a couple of weeks after my skin scan and neg. biopsy) - results negative.  He said there are other strains of herpes that wouldn't show up in those tests, so it's not ruled out.  However I don't think this acts like herepes in that it never festers into an open or wet sore - pretty much dry, peeling layers.

I started using a non-petroleum-based SPF-15 lip balm at the advice of the dermatologist.  Sometimes it seems to help the area, other times seems to aggravate it, so sometimes I stop using it for a few days, and in the colder weather neither using or not using it helps slow it down or stops the thickening.  I have experimented with different toothpastes (in case it's a chemical response) with some apparent but short-lived effects.

I'm concerned this is something serious developing.  It just seems that something lingering like this, continuously cycling, and never totally going away may not be good, and it does get painful in the colder weather.  Any suggestions?  Any tests to be done, or theories?  Could getting a second opinion from another dermatologist possibly result in some more definitive diagnosis and possible treatment/avoidance of serious problems?

Thanks for any info. and suggestions.

[Peva]

Well alrighty then.