Acne vulgaris, commonly known as pimples, is a chronic inflammatory skin disease of the sebaceous glands of hair follicles that occurs in adolescence. It has an incidence of 86-90% and has a significant psychological and social impact on adolescents. Early treatment of this disease is important, and timely and standardized diagnosis and treatment can shorten the course of the disease and avoid or reduce the occurrence of various complications. 1.Pathogenic factors of acne The occurrence of acne is mainly related to excessive sebum secretion, blockage of hair follicle sebaceous gland duct corpuscles, bacterial infection and inflammatory response, as well as diet, emotions, drugs and many other factors. 2. Clinical manifestations of acne Acne can be manifested as blackheads, whiteheads, inflammatory papules, pustules, nodules, cysts and so on. After acne heals, it is easy to form pigmentation, i.e. acne marks, enlarged pores or even scar-like damage, which can affect beauty or even disfigure the face. 3.Grading of acne The grading of acne helps to evaluate the treatment and efficacy of acne. According to the nature and severity of the lesions, acne can be classified into 3 degrees and 4 grades: Grade 1 (mild): acne only Grade 2 (moderate): acne + inflammatory papules Grade 3 (moderate): acne + inflammatory papules + pustules Grade 4 (severe): acne + inflammatory papules + pustules + nodules, cysts or scars 4. Mild acne refers to acne with only pimples, whiteheads or blackheads, and does not require systematic medication. Topical retinoic acid preparations can be used, and attention should be paid to eating less spicy and irritating food, removing oil and dirt from the skin surface, and keeping the bowels clear of all triggering factors. However, do not often squeeze acne to avoid infection and aggravation of the lesions. Grade 2 acne can be treated with topical agents such as retinoic acid and other drugs that regulate normal cellular keratinization, and topical antibiotics such as benzoyl peroxide if there are few inflammatory papules. In order not to leave complications such as a large number of acne marks and keloid pits, it is best to combine physical therapy, such as red and blue light and photodynamic therapy, with drug therapy (antibiotics, isotretinoin, etc.). If necessary, short-term application of glucocorticoids is also required. ③Physical therapy for acne For patients who cannot tolerate medication or do not receive medication, and for patients with grade 4 acne, physical therapy or combined physical therapy is a good choice. The physical treatments carried out in our department include: photodynamic therapy, red and blue light, fractional laser, bean pressure combined with blood pricking and cupping, etc. Red and blue light treatment for acne is based on the characteristics of the light action of Propionibacterium acnes, that is, Propionibacterium acnes can produce endogenous fecal bacillus and can absorb pro-bacillus through its cell wall receptors. Propionibacterium inactivates and plays a role in the treatment of acne. Photodynamic therapy is an exogenous photosensitizer, such as ALA, applied topically to the lesion, which is absorbed through the follicular sebaceous gland unit and participates in the hemoglobin synthesis pathway to produce protoporphyrin, which is excited by specific wavelengths of light to produce monomorphic oxygen and free radicals, thus selectively acting on the follicular sebaceous gland unit and Propionibacterium acnes with minimal damage to the surrounding tissue. The advantages of acne phototherapy: 1) Reduction of the systematic application of drugs and avoidance of drug-induced adverse reactions. 2) Effective options for special populations, such as pregnant women (except photodynamic) and others who cannot tolerate drug treatment. 3) No pain or other suffering. 4) While treating acne, it can smooth out fine lines, brighten skin tone, and make skin smoother and softer. ④ Treatment of post-acne scarring Severe and persistent acne is very likely to leave behind acne marks and even scarring such as pits of varying sizes, causing great psychological and social obstacles to patients. In the past, post-acne scarring was generally treated with grinding, but the treatment was not ideal because of the large invasive area and the number of treatments. The introduction of fractional laser in our department can improve the depressed scars left after various diseases. 5, acne patients daily life precautions 1) Avoid emotional tension and keep a happy mood. Ensure sufficient sleep. 2) Minimize the consumption of greasy, fried foods, sugar, chocolate and spicy, stimulating foods. Eat more vegetables and fruits rich in vitamin C and foods rich in calcium. 3) Pay attention to personal hygiene, avoid scratching and squeezing, and wash your face with warm water, but frequent washing will aggravate acne. 4) Avoid taking medications that may cause or aggravate acne. 5) Avoid using thick cosmetics and excessive makeup.