White spots on the lips can be seen in the following diseases.
White spots on the mucous membranes, mouth ulcers, hand, foot and mouth disease, sebaceous gland ectopia, vitiligo, whiteheads and herpes in the corners of the mouth.
fungal infections of the corners of the mouth such as pityriasis florida.
pityriasis simplex a.k.a. pityriasis alba (not associated with fungal infection), anaemic nevus.
Non-pigmented nevi.
Post-inflammatory hypopigmentation, senile leukoplakia, etc.