Lining mucosa: . The lining mucosa covers the lips, cheek, floor of the mouth, undersurface of the tongue and the soft palate.
this is from scientific literature!
The overgrowth is on entire lining mucosa, that is why we can see white coating near the junction of lips, the white coating is also forming every where but the constant saliva flow is cleaning, thats why we are unable to notice. Lips are just part of oral mucosa, because lips are not wetted by saliva, hence they are drying and crusting due to infection. Its not recommended to wet the lips with saliva, it complicates the exfoliative cheilitis many folds.