1.What is pigmented skin disease? Pigmented dermatosis is a common type of skin disease caused by a decrease or increase in pigmentation, and can be caused by genetic and environmental factors. Although most pigmented dermatoses do not pose a major health risk, they are a cosmetic hindrance and cause mental stress to patients, affecting their work, study and life. 2.What types of pigmented skin diseases are there? Lack of melanin can cause general or local skin whitening, such as vitiligo; increased melanin can cause pigmentation skin diseases, such as nevus of Ota, brown nevus, coffee spot, freckle, age spot, chloasma, tattoo, post-inflammatory hyperpigmentation, melanosis, etc. 3.How should pigmented skin diseases be treated? According to the size, depth, location and type of skin lesions, the following treatments are generally chosen. 1.Laser – Q-modulated laser, exfoliating/non-exfoliating fractional laser, dye laser, etc. 2.Strong pulse – photorejuvenation 3.Surgical skin treatment – excision, epidermal grafting Abrasion 4.Chemical peeling – fruit acid skin rejuvenation