i have had bumps on my lips, not white though. It happens when they are inflamed(itchy, red, swollen etc). They are like pimples and when they burst... a clear fluid comes out, which i assumed is sebum but is probably mucus to fight infection.
Can you explain exactly how the spots looks? are they on the effected area on the lips only?
it might not be fordyce spots, it could be e.g. a yeast... if your certain it's fordyce spots.. that is valuable info...