Acne, commonly known as “pimples,” is a chronic inflammatory skin disease of the sebaceous gland units of hair follicles, mainly in adolescents, and has a great impact on their psychology and social life. If it is not treated properly or actively prevented and treated, it can easily leave damage such as discoloration and scarring, leaving lifelong regrets. If early prevention and treatment can be done scientifically and reasonably, disfiguring scarring and other damage can be avoided or minimized. So, how to properly prevent and treat acne? First, we should learn to recognize acne. People may wonder, “acne” we do not know? However, in clinical work, we often find that patients simply take some red pimples or pus heads as acne, and think that blackheads, whiteheads, cysts, etc. are not acne. In fact, the clinical manifestations of acne are characterized by polymorphic lesions such as pimples, papules, pustules, and nodules, which are commonly found on the face. In addition, patients often ask, “Doctor, is my acne serious?” . We will address these questions below. Acne classification is an important basis for acne treatment and efficacy evaluation. According to the nature and severity of acne lesions, acne can be divided 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 causes of acne are closely related to excessive sebum secretion, blockage of hair follicle sebaceous ducts, bacterial infection and inflammatory reactions. After puberty, the level of androgens in the body, especially testosterone, rises rapidly, promoting the development of sebaceous glands and producing large amounts of sebum. At the same time, abnormal keratinization of the hair follicle sebaceous gland ducts causes duct blockage, resulting in obstruction of sebum drainage and formation of keratin plugs or microcomedones. A variety of microorganisms, especially Propionibacterium acnes, proliferate in the hair follicles. The lipase produced by Propionibacterium acnes breaks down sebum to produce free fatty acids, which also chemotactic inflammatory cells and mediators, ultimately inducing and aggravating inflammatory reactions. In general, acne is mainly related to endocrine disorders (androgen secretion), poor diet and rest habits (frequent late nights, excessive stress, consumption of spicy and stimulating, greasy food), and so on. Third, how to treat acne 1, daily care Maintain good living and eating habits and a happy mood. Wash your face with warm water once or twice a day, or use some cleanser to remove oil and acne, and avoid squeezing or scratching the lesions with your hands. Do not use oily or powder cosmetics, ointments and creams containing glucocorticoids. 2. Graded treatment of acne (1) Grade 1 is generally treated topically, with topical retinoic acid preparations (retinoic acid cream, adapalene gel, tazarotene gel) preferred. (2) Grade 2 combines topical retinoids and benzoyl peroxide or antibiotics, combined with oral antibiotics if necessary (minocycline, doxycycline, etc. preferred, followed by macrolides, antibiotic course usually 6-12 weeks). (3) Grade 3 often requires combination therapy, with oral antibiotics combined with topical benzoyl peroxide and/or retinoids being preferred. Antiandrogen therapy may also be considered in female patients with indications. (4) Grade 4 oral isotretinoin (Tylenol) is the most effective treatment and can be used as first-line therapy. The course of treatment is aimed at achieving a minimum cumulative dose of 60 mg/kg (more than six months for a normal 60 kg body weight patient if taking 2 capsules a day). For those with more inflammatory papules and pustules, systemic antibiotics combined with topical benzoyl peroxide may also be applied first, and then switched to sequential treatment with oral isotretinoin after significant improvement of the lesions.