Acne is a chronic inflammatory skin disease of the sebaceous glands of the hair follicles with a prevalence of 70% 87%, and has a psychological and social impact on adolescents that exceeds that of asthma and epilepsy. Treatment options for acne vary widely among clinicians, with some treatments having uncertain efficacy, lacking evidence-based medical evidence to support them, and individual approaches even causing damage to patients. Therefore, it is essential to develop a set of proven guidelines for the treatment of acne to standardize its treatment.
1. Pathophysiology of acne
Acne is a chronic inflammatory disease of the sebaceous units of the hair follicles, and the pathogenesis is still not fully elucidated. Genetics, androgen-induced sebum production, follicular sebaceous gland duct keratinization, Propionibacterium acnes colonization, inflammation and immune response may all be relevant.
2.Grading of acne
Acne grading is an important basis for acne treatment and efficacy evaluation. For simplicity and convenience in clinical use, this guideline classifies acne into 3 degrees and 4 grades mainly based on the nature of lesions: mild (Grade I): acne only; moderate (Grade II): inflammatory papules; moderate (Grade III): pustules; severe (Grade IV): nodules and cysts.
3.Patient education
Health education
① Diet: Limit spicy and sweet foods that may trigger or aggravate acne, and eat more vegetables and fruits;
② Daily life: Avoid staying up late, long-term exposure to computers, sun exposure, etc. Pay attention to facial skin cleaning, moisturizing and reducing sebum secretion, and keep bowel movements smooth;
③Psychological counseling: Patients with acne, especially those with severe acne, are more prone to anxiety, depression and other psychological problems, so these patients need to cooperate with the necessary psychological counseling.
Local cleansing
Choose water or a suitable cleansing product to remove excess oil, flakes and bacteria from the skin surface, but do not wash excessively. Do not squeeze or scratch lesions such as acne and inflammatory papules} with your hands.
Daily care
Some acne patients have a damaged skin barrier, and long-term oral or topical anti-acne medications such as retinoic acid often aggravate the destruction of the skin barrier and lead to skin sensitivity. Therefore, in addition to medication, physical therapy, and chemical peels, it is sometimes necessary to use efficacious skin care products in combination to maintain and repair the skin barrier function. If accompanied by skin sensitivity, topical soothing and oil-control moisturizing creams should be used, and skin care products with anti-acne effects can be used on local lesions; if the skin shows symptoms such as greasiness and enlarged pores, oil-control moisturizing gel should be mainly used.
4.Topical treatment of acne
Topical drugs
Topical retinoids
Topical retinoids have the ability to regulate the differentiation of epidermal keratin-forming cells, improve the keratinization of hair follicle sebaceous ducts, dissolve microcomedema and acne, and anti-inflammatory effects, as well as control post-inflammatory hyperpigmentation and improve acne scarring. Topical retinoids are the first-line drugs for mild acne, the first-line drugs for moderate acne, and the drugs of choice for acne maintenance treatment.
Currently, commonly used topical retinoids include first-generation retinoids such as 0.025% to 0.1% all-trans retinoic acid cream or gel and isotretinoin gel, and third-generation retinoids such as 0.1% adapalene gel.
Adapalene is better than all-trans retinoic acid and isotretinoin in terms of tolerability and safety. It is more effective than all-trans retinoic acid in non-inflammatory lesions and can be used as the first-line choice of topical retinoids for acne. Topical retinoids often cause mild skin irritation, such as local erythema, flaking, tightness and burning sensation, but may gradually disappear with prolonged use. It is recommended to be used at low concentrations or in small areas, once a night, away from light.
Benzoyl Peroxide
It is a peroxide that slowly releases neo-oxygen and benzoic acid after topical application, which has the effect of killing Propionibacterium acnes, dissolving acne and astringent. It can be formulated as a lotion, emulsion or gel in different concentrations of 2.5%, 5% and 10%. A few sensitive skins may experience mild irritation, so it is recommended to start with a low concentration and a small trial for sensitive skins. Benzoyl peroxide can reduce the occurrence of drug resistance in Propionibacterium acnes and can be used as one of the topical antibacterial drugs of choice for inflammatory acne if tolerated by the patient. This drug can be used alone or in combination with topical retinoids or topical antibiotics.
Topical antibiotics
Commonly used topical antibiotics include erythromycin, lincomycin and its derivatives clindamycin, chloramphenicol or clindamycin, etc. Prepared with ethanol or propylene glycol at a concentration of 1% to 2%, they are more effective. 1% chloramphenicol phosphate brew solution is a water-soluble emulsion that does not contain oil and ethanol and is suitable for acne patients with dry and sensitive skin.
In recent years, it has been found that topical fusidic acid cream has good killing effect and anti-inflammatory activity on Propionibacterium acnes, and it has no cross-resistance with other antibiotics, so it can also be used as one of the topical antibiotics for acne treatment. Since topical antibiotics are prone to induce resistance in Propionibacterium acnes, they are not recommended for use alone, but in combination with benzoyl peroxide or topical retinoids.
Disulfurization
2.5% disulfide sunscreen has the effect of inhibiting fungi, parasites and bacteria, and can reduce the free fatty acid content of the skin. After cleansing the skin, apply the solution with slight dilution evenly on the parts with significant seborrhea, and wash with water after 3~5min.
Other topical drugs
5%-10% sulfur lotion and 5%-10% salicylic acid cream or gel can be used for acne treatment because they inhibit Propionibacterium acnes and have a slight exfoliating and antibacterial effect. Topical antibacterial and anti-inflammatory medications are generally recommended for spot application on lesions, while topical retinoids are recommended for simultaneous application on lesions and acne-prone areas due to their anti-microcomedogenic effects. Treatment usually takes 8 to 12 weeks or longer.
Chemotherapy
Fruit acids have been used as chemotherapy in acne treatment with positive results. Fruit acids are widely found in fruits, sugar cane and yogurt. They have a simple molecular structure, small molecular weight, are non-toxic and odorless, and have strong penetration and safe action. Its mechanism of action is to reduce the adhesion of keratin-forming cells by interfering with the binding force of cell surface, accelerate the shedding and renewal of epidermal cells, regulate the secretion of sebaceous glands, and stimulate the synthesis of dermal collagen, increase mucopolysaccharide and promote tissue repair.
Treatment protocol: Application of glycolic acid (also known as glycolic acid, derived from sugar cane) at 20%, 35%, 50%, and 70% concentrations to treat acne, with increasing concentrations or dwell time depending on the patient’s tolerance level. Treatment is given once every 2-4 weeks, with 4 sessions being a course of treatment. It is effective for both inflammatory and non-inflammatory lesions. After fruit acid treatment, localized light erythema, white cream, swelling, stinging and burning sensation may appear, all of which can be recovered within 3-5 d. If post-inflammatory pigmentation occurs, it will take 3-6 months to recover. Pay attention to sun protection during the inter-treatment period.
Physical therapy
Photodynamic therapy (PDT): Topical 5-aminoketovaleric acid (ALA) is enriched in the sebaceous gland units of hair follicles and is metabolized by the heme synthesis pathway to produce the photosensitive substance protoporphyrin IX, which is irradiated by red light (630 nm) or blue light (415 nm) to produce monomorphic oxygen that acts on the sebaceous glands to cause sebaceous gland atrophy, inhibit sebum secretion, directly kill pathogenic microorganisms such as Propionibacterium acnes, and improve It directly kills Propionibacterium acnes and other pathogenic microorganisms, improves hyperkeratinization of keratin-forming cells at the mouth of the hair follicle and obstruction of the opening of the sebaceous glands of the hair follicle, promotes the healing of skin lesions and prevents or reduces acne scarring.
Indications: Grade III and IV acne, especially acne patients with fatty liver, hepatic impairment or hyperlipidemia. It is necessary to avoid light for 48h after surgery to avoid phototoxic reactions. Patients with mild to moderate lesions can be treated directly with LED blue light or red light.
Laser therapy: A variety of near-infrared wavelength lasers, such as 1320 nm laser, 1450 nm laser and 1550 nm laser are commonly used to treat acne inflammatory lesions, with the appropriate energy density and pulse width selected according to the degree of inflammation of the lesions. Intense pulsed light and pulsed dye lasers help the red marks in the later stages of inflammatory acne to fade.
Non-ablative fractional lasers (1440 nm laser, 1540 nm laser and 1550 nm laser) and ablative fractional lasers (2940 nm laser, 10600 nm laser) have shown some degree of improvement in acne scarring. For clinical application, it is recommended to choose small spot, lower energy and low fractional density for multiple treatments.
Other treatments
Acne removal:Acne can be squeezed out with an acne squeezer of choice along with topical medication. When squeezing, attention should be paid to the aseptic operation and to the force and direction of squeezing. Improper force can cause rupture of the sebaceous capsule, resulting in inflammatory papules.
Intracapsular injection: For severe cystic acne, in addition to medication, intracapsular injection of tretinoin acetate + 1% lidocaine can bring about rapid relief, once every 1 to 2 weeks. Prevention of local skin atrophy and secondary bacterial infection is required for multiple injections.