I. Why is acne graded? Acne is a chronic inflammatory skin disease of the sebaceous glands, with a prevalence of 70% to 87%. Dermatologists vary greatly in their treatment choices for acne, and some treatments are uncertain in their efficacy and lack a basis in the literature for clinical trials; some even harm patients, creating a bad social impact and causing economic damage to patients. Acne grading is an important basis for acne treatment and efficacy evaluation. Therefore, when addressing a specific patient, clinicians should fully understand the best clinical evidence and available medical resources for this disease, and develop a reasonable treatment plan based on their knowledge and experience, taking into account the patient’s specific condition and his or her wishes in a comprehensive manner. According to the nature and severity of acne lesions, acne can be classified into three grades: Grade 1 (mild): acne only; Grade 2 (moderate): inflammatory papules in addition to acne; Grade 3 (moderate): pustules in addition to acne and inflammatory papules; Grade 4 (severe): nodules, cysts or scarring in addition to acne, inflammatory papules and pustules. The grading of acne reflects the severity of acne and the nature of the lesions, so the treatment of acne should be based on the grading of acne and the selection of appropriate treatment drugs and means. Whether acne is graded according to the International Modified Classification Method, which is based on the number of lesions, or according to the Acne Classification Method, which emphasizes the nature of lesions, the choice of treatment options is basically the same. Of course, the treatment plan for acne is not set in stone and should be flexible according to the actual situation of the patient, fully reflecting the principle of individualized treatment. Grade 1: Topical treatment is generally used. If only acne is present, topical vitamin A acid preparations are the best choice. Some medical skin care products that have the effects of exfoliating, dissolving acne, inhibiting sebum secretion, and antibacterial can also be used as an adjunctive treatment. Grade 2: Treatment for grade 1 acne is usually used, but oral antibiotics can be used for those with more inflammatory papules and pustules and where topical treatment is not effective. This type of acne can also be treated with combination therapy, such as oral antibiotics combined with topical retinoic acid preparations, or combined application of physical therapy such as blue light, photodynamic therapy, and fruit acid therapy. Grade 3: These patients often require a combination therapy approach, in which the systematic use of antibiotics is one of their basic treatments, and an adequate course of treatment should be ensured. The most frequently used combination therapy is oral antibiotics combined with topical retinoic acid preparations, and also topical peroxymethylphenidate can be used at the same time. The use of hormonal therapy for female patients requiring contraception or with other gynecological indications has also been shown to be effective. Other combination therapies introduced by me can also be used, such as red and blue light and photodynamic therapy, but attention should be paid to the interactions and contraindications between tetracyclines and isotretinoin drugs, as well as the development of photosensitivity. Those with poor results can be treated with oral isotretinoin alone or with concomitant topical peroxynivalenol. For those who need more than 3 months of systemic antibiotic application, it is necessary to combine such antibacterial agents that do not cause bacterial resistance as peroxymethylphenidate to prevent and reduce the development of drug resistance. Grade 4: Oral isotretinoin is the most effective treatment for this group of patients and can be used as first-line therapy. For patients with more inflammatory papules and pustules, a combination of systemic antibiotics combined with peroxynivalenol can also be applied first, and then switched to oral isotretinoin for lesions such as cysts and nodules after the lesions have improved significantly. You can also try the methods used for grade 3 acne mentioned above and the combination treatment method I introduced.