Horsie, you win the February prize for the least English-as-a-second-language-friendly thread title! ;-)
Regarding the way that cheilitis exhibits itself and changes over time, I have found that the three things (so far) that cause my lips to flare up each have a different effect on my lip skin.
Back when I was using all 3 things at once (and didn't realize they were causing me trouble), my lips were really bad, but my lips would go through different "looks" and changes (kind of like your description of having a fever/illness). At that time, there wasn't any pattern that I could see - it was all over the map.
Now that I have isolated 3 things that seem to cause my lips to have cheilitis, and I've given the lips time to heal between exposures, I can see that each substance has a different effect on my lips.
The Boots tea tree antibacterial cream gave me lots of flaking off pieces constantly, oval-ish, about 1/4th of an inch in diameter, starting from about 1 day after exposure and going until about 4 days after exposure. The worst time would be about 2 days after exposure. It seemed to be a delayed process at the start - it would take a day after exposure for anything to happen. (That might be because exposure was not directly to the lips - it was to another area of my body, so I guess it had to travel internally, or the immune system needed time to think about the insult before it reacted on its "favorite" billboard of my body.) There was never a point when the healing seemed dramatic - the healing was gradual and just more of the same, only softer and softer, day by day.
The alpha hydroxy acids (ahas) gave me a tight, dry, pinched lip surface for a couple of days after exposure (no flaking during that time, just a dry, crinkled surface), and thereafter, over the course of one whole day, several layers would peel off spontaneously in about 1/4th inch strips, across my bottom lip horizontally. The healing was more dramatic - after the 1 day of layers peeling off, on about day 4 or so my lips would appear relatively calm, although they looked old and tired from being put through the ringer.
The cut-vegetable seeming-allergy, which probably was to garlic, flared up after only about 30 minutes after the lips had exposure to the substance, and the lips began to burn a little. The top layer of the lip started to flake, and some bloody vertical fissures developed on their own, dramatically. After a couple of hours, it was quite bad. In the few days afterward, the lip then acted much like it does from the Boots tea tree antibacterial cream - oval flakes, general uneven surface, dismay. This took a couple of days to subside.
With all of these various exposures and allergic reactions, it took about a week of no-exposure-to-the-item and healing for the cheilitis to retreat to only being on a thin strip of my bottom lip (that edge of the lip that is towards the teeth, not towards the chin).
Additionally, I tried the dish soap/dish detergent method for a few days, using organic, non-anti-bacterial, color-free dish detergent, and when I was using this my lips dried out massively, the cheilitis didn't go away, AND the cheilitis spread from my lower lip to the corners of my lips and then up to a portion on either side of my upper lip. Because that alarmed me, I stopped washing with the dish detergent at that point, and the cheilitis retreated back to my lower lip only. So -- I understand your argument that if cheilitis spreads from lower to upper lip, it's probably from a migrating fungus/bacteria, but in my case, it spread due to exposure to a harsh treatment, and I think it would have continued to spread across my upper lip if I'd kept using the dish soap.
I think if the health and structural integrity of the lip skin is damaged due to injury, biting, corrosive saliva, chemicals, sunburn, dentist harshness, etc., and the lips have a tendency to cheilitis anyway, a newly damaged area is a fertile place for chelitis to start in and maybe become entrenched in. Spreading cheilitis is not necessarily the result of migrating fungus/bacteria.