A. Why leave acne marks on? Inflammatory rash causes capillary neovascularization (erythema), local metabolic dysfunction, and increased pigmentation (brown spots). Inflammatory rashes develop partly from acne, so acne should be treated aggressively at an early stage. Second, how to solve it? ”Comprehensive treatment, prevention of recurrence, attention to sun protection” 1. Inversion: using the principle of warmth to improve facial blood circulation, to achieve the role of anti-inflammatory, lipid removal, lightening pigmentation, relatively mild, for brown acne marks less effective, can be combined with light spot drug import treatment or red light to enhance the effect of removing marks. Generally once a week, treatment for more than 3 months. 2. Red light: It can reduce skin pigmentation, improve skin barrier function, stimulate collagen fiber and elastic fiber proliferation and rearrangement, and can be used to improve pigmentation and skin quality during acne recovery. Generally, 2 to 3 times per week, 10 times/treatment. 3.OPT light: It can be selectively absorbed by melanin and hemoglobin, targeting treatment with the best efficacy. It can also penetrate through the epidermis to the dermis and subcutaneous tissues, promoting collagen synthesis and rearrangement, thus increasing skin elasticity and improving texture. Therefore, OPT light can simultaneously treat various skin problems after acne: erythema; erythroderma; hyperpigmentation; mild depressed scarring; and dull skin tone, which can be said to be a multi-benefit, and this comprehensive advantage is unmatched by other methods.