Analysis of illness: vitiligo, pigmented nevus, anemic nevus, post-inflammatory hypopigmentation, pityriasis albiflora, tinea versicolor, etc. If you have white spots on your face and neck, you should consider them. First, make a preliminary diagnosis through the medical history. You can observe it by rubbing the white spot and the surrounding skin. If the white spot turns red, don't consider the pigmented nevus. White dots are still red. Consider anemic nevus. If leukoplakia has previous trauma or skin inflammation, consider discoloration after inflammation. Secondly, it is judged by whether there are scales on the surface of the rash. If there are scales on the surface, consider pityriasis alba or tinea versicolor. Tinea versicolor tends to grow in places rich in sebum.