Fordyce spots explained

"The sebaceous gland is responsible for the formation of these spots on the lips.
When the ectopic sebaceous gland becomes full with pus or oil, it results in the appearance of whitish or yellowish spots on the lips.
This condition is called sebaceous hyperplasia."

I think there is more to these spots like allergic inflammation in some, but this article explains how these spots appear in puberty.

"The spots are congenital in nature meaning it is present from birth but appears for the first time during puberty when sebaceous glands are highly active.
Once present, the spots often persist throughout the person’s lifetime.
However, with age, the spots decrease and fade."

http://www.simple-remedies.com/home-remedies/discoloration-of-teeth-and-lip-c...

Maybe these spots create a chronic bacteria infection or cause too much oil for skin to grow back normally in the area. I don't know how well a wound could heal in constant bacteria oil or pus.