why the upper lip might be extra moist
Fordyce spots are present at birth, but they don't become prominent until adulthood. Fordyce spots are small, yellow or white spots that develop in groups on moist tissue such as the lips, in the mouth, tongue, cheeks, female labia, and the penis. You may sometimes find it on the lower lip as well, even though it is rare. They are caused by an overgrowth of the sebaceous glands. These are large sebaceous glands without hair follicles, which are called ectopic sebaceous glands. Basically, ectopic means occurring in a place other than where typically expected. Sebaceous glands are your oil (sebum) producing glands, (i.e. oil from hair follicles). In this case, the sebaceous glands are ectopic, occurring at the surface of the skin. Sebum lubricates and protects the hair and skin and prevents drying and irritation of membranes. Sebum may collect excessively as a result of poor hygiene, a diet rich in fats, or accelerated glandular activity.
I wondered why the raw, triangular area of upper lip was always moist. The moistness prevented a scab from forming to heal that area. It was probably really moist because that is where I had groups of fordyce spots, which produced oil. I had no fordyce spots on my lower lip so it was not moist. It takes longer for an overmoist area to heal. After each new layer of skin formed, a little moistness was still coming out. It was not until more layers built up that acted as plug so no more oil could leak out. I can't explain why it is not moist where people have fordyce's spots on lower lip, though. Maybe they have less fordyce spots there. Or they are higher up at surface layer so they do not interfere with new skin growth like having them deeper in skin does. I just had so many spots concentrated on upper lip.