Acne, also known as “pimples”, seriously affects the aesthetics of patients, and in severe cases, even affects their quality of life, social life, depression, etc. Photodynamic technology is a new technology that has been internationally recognized as a safe and effective treatment for acne in recent years. Many patients have many years of failed acne experience and do not know much about this technology, so they have certain doubts about the treatment. A. What is acne all about? Acne is a chronic inflammatory disease involving the skin follicles and sebaceous glands. It is often seen during adolescence and is therefore called “acne”. The causes of acne are complex and are the result of a combination of pathogenic factors, including excessive sebum secretion, abnormal epithelial desquamation of hair follicles, proliferation of Propionibacterium acnes and inflammatory reactions. The epidemiological survey of acne this year found that the prevalence of acne among adolescents aged 11-25 is more than 80%, and among young people aged 25-35 is more than 15%. If left untreated or improperly prevented, acne marks and scarring can remain for life, affecting the appearance. Patients often have anxiety, irritability, lack of self-confidence leading to a decline in the quality of life, serious impact on the patient’s social function, such as social fear, academic performance, decline, unemployment, etc., so the battle “acne” can not wait. What is photodynamic technology? Photodynamic technology, also known as photodynamic therapy and Ira photodynamic therapy, is a new technology that selectively destroys Propionibacterium acnes and repairs the skin through a photodynamic reaction by combining the application of 5-aminoketovaleric acid and the corresponding light source. First, a colorless, odorless, non-irritating photosensitizer “Ira” is applied to the acne-prone area, and then the light is blocked with a photosensitizing eardrum, resting for 1-2 hours like a mask on a regular basis, allowing the photosensitizer to slowly and fully penetrate into the hair follicles and sebaceous glands. The photochemical reaction takes place at the onset of the disease, directly killing Propionibacterium acnes, inhibiting sebum production, anti-inflammatory, and promoting collagen synthesis and repair. This is a normal reaction to photodynamic therapy. After the photodynamic therapy is completed, the redness and burning sensation will gradually disappear after 30 minutes of hydrotherapy. Each photodynamic treatment process takes about 3 hours. 10-15 days to do once, most patients can do 3 times to achieve more satisfactory results, some serious patients need several consecutive treatments to achieve satisfactory results. After each treatment, you need to protect yourself from the sun for 2-3 days and try to go out between 9:00 a.m. and 4:00 p.m. Third, what types of acne are suitable for photodynamic therapy? Photodynamic therapy is most suitable for moderate to severe acne with mainly papules, pustules and nodules; refractory acne that has been ineffective after multiple treatments; acne patients with gastrointestinal diseases, poor liver and kidney function and other underlying diseases; acne patients who are growing and developing and allergic to antibiotics. The advantages of photodynamic technology: (1), fast, safe, no side effects, no nausea, depression, thirst, etc. for local treatment compared to the systemic treatment (oral medication) program. (2), Reduce sebum secretion and contribute to self-inflammation to achieve rapid elimination of acne and acne marks. (3).Reducing pores, reducing pigmentation, and smoothing out fine wrinkles in the skin. (4).Enhance skin elasticity and make the skin smooth and moist. (5), The treatment process is gentle and non-irritating, the patient feels comfortable, and the treatment is fast and effective.