【Abstract】 Chronic pruritus is a common symptom of various diseases, causing severe negative impacts on patients′ quality of life. Due to its complex pathogenesis, etiological diagnosis and treatment are often challenging. To improve the understanding of chronic pruritus among Chinese clinicians and to standardize diagnosis and therapeutic practices, the China Dermatologist Association organized experts in China to update the classification, etiology, and pathogenesis of chronic pruritus based on the "Guidelines for the Management of Chronic Pruritus （2018 edition）" , current research status and progress in China and other countries, as well as extensive consultation with experts in China through the Delphi method, aiming to provide expert opinions and evidence-based medical guidance on the etiological diagnosis and treatment of chronic pruritus.

【Abstract】 Atopic dermatitis is a common chronic recurrent inflammatory skin disease. Previous therapeutic drugs include topical glucocorticoids, topical calcineurin inhibitors, oral antihistamines, systemic immunosuppressants and glucocorticoids, etc. In recent years, biologics and a variety of small-molecule drugs have been approved for the treatment of atopic dermatitis. Based on recent research progress, Chinese and international guidelines or consensus, and experts′ clinical experience, China Dermatologist Association, Chinese Society of Dermatology, Dermatology Branch of China International Exchange and Promotive Association for Medical and Health Care, State Key Laboratory of Complex Severe and Rare Diseases, and National Clinical Research Center for Dermatologic and Immunologic Diseases convened experts to develop this consensus on strategies for the clinical application of therapeutic drugs for atopic dermatitis, monitoring and management of adverse drug reactions, and drug management in special populations, aiming to provide a reference for the application and management of therapeutic drugs for atopic dermatitis.

【Abstract】 Atopic dermatitis （AD） is a chronic, relapsing, inflammatory skin disease that seriously affects patients' quality of life, and its incidence has shown an increasing trend in recent years. As one of the triggering factors of AD, allergens can lead to the recurrence or exacerbation of AD. Allergen-specific IgE （sIgE） tests can guide the long-term management of AD patients by identifying allergens. There are still many problems regarding the application of sIgE tests in AD clinical practice. Based on current Chinese and international guidelines and relevant research evidence, this consensus summarizes the clinical value of sIgE tests for AD patients and provides 9 recommendations on patient selection, selection of test methods and items, result interpretation, and some considerations, providing the standard principles for the application of sIgE tests in the diagnosis and treatment of AD in clinical practice in China.

【Abstract】 Mycoplasma genitalium can cause urogenital tract infections such as urethritis, cervicitis and pelvic inflammatory disease, which are associated with preterm birth. Due to difficulties in the culture of Mycoplasma genitalium, confirmation of its diagnosis relies on nucleic acid amplification testing. Increasing antibiotic resistance of Mycoplasma genitalium poses a great challenge for clinical treatment. To raise Chinese clinicians′ understanding of Mycoplasma genitalium infection and improve its diagnosis and treatment, the Hospital of Dermatology of the Chinese Academy of Medical Sciences, the National Center for STD Control of Chinese Center for Disease Control and Prevention, the Venereology Group of the Chinese Society of Dermatology, and the Chinese Association Rehabilitation of Dermatology organized relevant Chinese experts to formulate the consensus after thorough discussions on the etiology of, epidemiology of, clinical manifestations of, laboratory tests for, diagnosis and treatment of, follow-up and test of cure for, management of sexual partners for and prevention of Mycoplasma genitalium infection based on the latest international guidelines for the management of Mycoplasma genitalium infection and relevant research progress in China and other countries.

【Abstract】 Pemphigus is a group of rare and severe autoimmune bullous diseases characterized by blisters, bullae, and erosions on the skin and/or mucous membranes. With the deep understanding of pemphigus and continuous update of treatment methods, it is necessary to formulate guidelines for the diagnosis and treatment of pemphigus in China. Hence, a guideline working group was established by relevant academic organizations. Based on available evidence in China and other countries, as well as China's national conditions, 12 clinical issues that need to be urgently solved were proposed and 30 recommendations were formulated on the diagnosis and treatment of pemphigus after multiple rounds of demonstration and selection, aiming to provide a reference for the diagnosis and treatment of pemphigus and to guide clinical practice.

【Abstract】 The treatment of psoriasis has entered an era of targeted therapy, and the application of biologics and small-molecule drugs has markedly improved the quality of life of patients, especially in the treatment of moderate to severe, refractory, and special types of psoriasis. In China, biologics that have been approved for marketing and used in the treatment of psoriasis include 9 agents belonging to 5 major categories, namely tumor necrosis factor-α inhibitors, interleukin-12/23 inhibitors, interleukin-23 inhibitors, interleukin-17A inhibitors, and interleukin-36 inhibitors; small-molecule drugs include 4 drugs belonging to 2 categories that inhibit different steps in the inflammatory cytokine pathways, namely phosphodiesterase 4 and Janus kinases （including tyrosine kinase 2）. How to use biologics and small-molecule drugs in a rational, effective and safe way has become an issue of great concern in clinical practice. To this end, experts in the field of diagnosis and treatment of psoriasis and related fields in China developed this guideline based on Chinese and international research data, clinical experience, as well as characteristics of Chinese patients with psoriasis after in-depth discussions. This guideline provides specific guidance for clinicians in terms of application principles and methods of major biologics and small-molecule drugs, efficacy and safety profiles, patient screening and monitoring, common problems and solutions, as well as considerations for their application in special populations.

【Abstract】 Cutaneous tuberculosis is a chronic infectious skin disease caused by Mycobacterium tuberculosis complex. It has various clinical manifestations and is difficult to be accurately diagnosed. Delayed diagnosis may lead to serious damage to the skin and soft tissues. The diagnosis of cutaneous tuberculosis requires a comprehensive assessment of clinical, pathological, and laboratory findings. A long‐course combination antibiotic therapy is commonly needed for the treatment of cutaneous tuberculosis, and early standardized diagnosis and treatment are the key to ensuring a good prognosis. This expert consensus was developed based on Chinese and international literature and guidelines on cutaneous tuberculosis and tuberculosis, aiming to standardize the diagnostic procedure and improve the treatment outcomes of cutaneous tuberculosis.

【Abstract】 Chemical peeling has been widely used in the treatment of various skin diseases and skin rejuvenation. However, improper operation or non?professional practice may lead to irreversible adverse events. To enhance public understanding of chemical peeling and popularize correct and professional medical knowledge, an expert consensus group on the clinical application of chemical peeling in China co?established by the Chinese Society of Dermatology, China Dermatologist Association, Chinese Association of Integrative Medicine Board of Dermatovenereology developed this consensus on the definition, classification, indications, contraindications, adverse effects of, and considerations during the treatment with chemical peeling, aiming to provide a reference for the public.

【Abstract】 Tumor necrosis factor （TNF）-α inhibitors have become an important choice for patients with chronic inflammatory diseases who are intolerant or poorly responsive to conventional therapies. Studies have shown that psoriasis can develop or be exacerbated in 2% - 5% of patients treated with TNF-α inhibitors, and this phenomenon is called paradoxical psoriasis. Paradoxical psoriasis and classic psoriasis have similar clinical manifestations, but different immunological mechanisms. This review summarizes the pathogenesis, clinicopathological features and management of paradoxical psoriasis, and provides an overview of paradoxical psoriasis following the application of other common biological agents.

【Abstract】 Postinflammatory hyperpigmentation is a hyperpigmentation disorder following skin inflammation or damage caused by various endogenous and exogenous factors, which may result in emotional distress and social difficulties in patients. The Group on Medical Aesthetics and Cosmetology of Chinese Academy of Aesthetic Medicine organized experts in this field to develop this consensus in terms of the epidemiological characteristics, etiology and pathogenesis, clinical manifestations, prevention, and treatment of postinflammatory hyperpigmentation, aiming to provide guidance for its prevention and treatment.

【Abstract】 In recent years, with the in-depth study of pemphigus, new pathogenesis has been identified based on the desmoglein antibody-mediated immune response mechanism, and new progress has been made in targeted therapy. This review summarizes recent advances in the pathogenesis and targeted therapy of pemphigus.

【Abstract】 Erythrodermic psoriasis is a special type of psoriasis, characterized by diffuse erythema, infiltration, swelling and excessive desquamation throughout the body. It is often accompanied by systemic symptoms, leading to serious disease condition, and it is easy to relapse. Based on the latest Chinese and international guidelines and consensus, and combined with the current status of diagnosis and treatment in China, the expert committee established this consensus that focused on the etiology and pathogenesis, clinical manifestations, auxiliary examination, diagnosis, differential diagnosis and treatment of erythrodermic psoriasis, aiming to further standardize the diagnosis and treatment patterns of erythrodermic psoriasis, and provide a more scientific and authoritative reference for its diagnosis and treatment in China.

【Abstract】 Adverse skin reactions to cosmetics refer to local lesions or systemic damage involving the skin, mucosa, appendages and other tissues caused by the use of cosmetics. With the increasing variety and widespread use of cosmetics, the incidence of adverse skin reactions have been rising with increasing types of diseases and diverse clinical characteristics. To strengthen the understanding of adverse reactions to cosmetics, the guideline for the diagnosis and treatment of adverse skin reactions to cosmetics （2018 edition） was updated and revised by relevant experts based on literature search and evaluation, discussion, demonstration meetings, opinion solicitation, and other procedures, aiming to standardize clinical diagnosis and treatment of adverse skin reactions to cosmetics, as well as safety monitoring of cosmetics.

【Abstract】 Extramammary Paget′s disease （EMPD） is a rare and easily misdiagnosed cutaneous malignancy, which is usually confined to the epidermis and can also infiltrate the dermis in the early stage, and presents with lymph node and distant metastases in the advanced stage. EMPD mostly affects the areas rich in apocrine glands, including the scrotum, penis, and vulva, as well as perianal, inguinal and axillary regions. It typically presents as infiltrative erythema or plaques, some of which are accompanied by scales and erosions. Before the treatment, comprehensively assessing the staging of patients is necessary due to the treatment options depending on the tumor stages. Based on the latest international guidelines and clinical research findings, and taking into account the current status of diagnosis and treatment in China, experts reached a consensus on the first- and second-line treatments and novel treatments according to the staging of EMPD, providing a basis for standardizing the treatment of EMPD.

【Abstract】 The occurrence of Kaposi′s sarcoma （KS） is closely related to Kaposi′s sarcoma-associated herpesvirus （KSHV） infection of endothelial cells. KSHV infection can present as various types of KS, and clinical features, severity and prognosis differ among different types of KS. Classic KS is characterized by localized lesions and slow progression, AIDS-related KS and endemic KS are highly aggressive, and iatrogenic KS needs control of the primary disease during treatment. Therefore, individualized therapies should be developed according to the clinical classifications and characteristics of KS. This review summarizes treatment modalities of and research progress in KS.

【Abstract】 Nontuberculous mycobacteria （NTM） encompass all mycobacterial species except the Mycobacterium tuberculosis complex and Mycobacterium leprae. In recent years, the incidence of skin and soft tissue infections caused by nontuberculous mycobacteria has shown an increasing trend. It is prone to be misdiagnosed due to the lack of specificity of clinical manifestations. This consensus aims to improve Chinese clinicians′ understanding of nontuberculous mycobacterial diseases and standardize their diagnosis and treatment.

【Abstract】 Chlamydia trachomatis urogenital infection can initially cause cervicitis in women and urethritis in men, and then lead to severe complications in the upper reproductive tract, such as prostatitis, epididymitis, pelvic inflammatory disease, etc., resulting in serious consequences such as ectopic pregnancy and infertility. Maternal infection is associated with serious adverse outcomes in neonates, such as preterm birth, low birth weight, and pneumonia. Due to the silent persistence of infection, many infected people go undetected and untreated. In order to improve the understanding, diagnosis and treatment of this disease among clinicians in China, the Chinese Society of Dermatology, National Center for STD Control of Chinese Center for Disease Control and Prevention, China Dermatologist Association, and Chinese Association Rehabilitation of Dermatology convened relevant experts to develop this guideline after thorough discussions and repeat revisions according to recent literature in China and other countries. This guideline summarizes epidemiological changes, clinical manifestations and classification, evidence and recommendations for the diagnosis and treatment of, as well as follow-up and cure assessment criteria for Chlamydia trachomatis urogenital infection, aiming to provide suggestions and references for medical workers at all levels.

【Abstract】 In recent years, great progress has been made in the research on the pathogenesis of pruritus, and many new targeted therapeutic drugs have been developed, mainly including small-molecule drugs or biological agents targeting signal transduction pathways involved in the pathogenesis of pruritus, such as neurokinin-1 receptor, tropomyosin-related kinase A, transient receptor potential vanilloid 1, transient receptor potential melastatin 8 channels, interleukin 31, etc. Some of these drugs have shown good efficacy and safety in the treatment of pruritus in a variety of skin diseases, providing more options for patients with pruritus, especially those who are resistant to traditional drug treatment. This review summarizes research progress in the above small-molecule drugs and biological agents targeting signaling pathways involved in pruritus, in order to provide more options for pruritus treatment.

【Abstract】 In recent years, targeted therapy and immunotherapy have been applied more and more widely in tumor treatment, and reports on psoriasis induced or exacerbated by these drugs have emerged continuously. This review summarizes and evaluates targeted therapeutic drugs and immunotherapeutic drugs that allegedly induce or aggravate psoriasis according to their targets and possible mechanisms, including programmed death receptor 1 inhibitors, epidermal growth factor receptor inhibitors, human epidermal growth factor receptor 2 inhibitors, anti-CD20 monoclonal antibodies, phosphoinositide 3-kinase δ inhibitors and multi-targeted drugs. In most cases, the relationships between drugs and the occurrence of psoriasis are possible or probable, and in only a few cases the causality is certain.

【Abstract】 Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit. Androgen-induced sebum secretion, hyperkeratosis of the pilosebaceous duct, microbial overgrowth in hair follicles, and inflammatory and immune reactions are closely associated with the pathogenesis of acne. However, the pathogenesis and pathophysiological processes of acne remain unclear. With the progression of scientific research, the conventional understanding of acne has been constantly updated in recent years, while clinical treatment principles underwent several transformations as well. This article aims to review some latest theories on the pathogenesis of acne vulgaris and their implications in prevention and treatment from the perspectives of sex hormone levels, hair follicular microorganisms, hair follicle stem cells and pathogenesis of severe acne, so as to provide new directions and ideas for the prevention and treatment of acne vulgaris.

【Abstract】 The degree of severity varies greatly among different patients with acne inversa（AI）/hidradenitis suppurativa（HS）, and disease severity usually determines treatment strategies. There have been a number of severity assessment criteria for AI/HS, such as the Hurley grading system, Sartorius score, HS severity index, etc., which have been widely used in clinical classification and research and have shown clinical guiding significance. However, limitations still exist in some criteria, such as low sensitivity for efficacy evaluation, limited application range, etc. This review introduces several severity assessment criteria for AI/HS that have been proposed in recent years, aiming to better evaluate the disease and carry out graded treatment.

【Abstract】 Drug-resistant dermatophyte infections are a hotspot issue in the fields of clinical microbiology and dermatology. Cases of antifungal-resistant dermatophyte infections have emerged in China, predicting a risk of transmission among humans. Based on the existing medical evidence and research data, the Mycology Group of Combination of Traditional and Western Medicine Dermatology and Chinese Antifungal-Resistant Dermatophytosis Expert Consensus Group organized experts to make recommendations and develop the consensus on the pathogenicity, epidemiology, identification, in vitro drug susceptibility test of antifungal resistance dermatophytes, and the diagnosis, treatment, prevention and control of the infections. Further, complete diagnosis and treatment recommendations were made in the consensus, aiming to provide a scientific reference for the clinical diagnosis, treatment, prevention and control of drug-resistant dermatophyte infections in China.

【Abstract】 Narrow-band ultraviolet B （NB-UVB） phototherapy has been regarded as the first-line treatment of generalized vitiligo. However, NB-UVB monotherapy exhibits limited efficacy with a long course of treatment. NB-UVB phototherapy combined with other therapies can shorten the course of treatment and improve the therapeutic effect, and has become a commonly used therapeutic regimen in clinical practice. This review summarizes research progress in NB-UVB combined with other therapies for the treatment of vitiligo, such as glucocorticoids, afamelanotide, calcineurin inhibitors, Janus kinase inhibitors, platelet-rich plasma, fractional carbon dioxide laser and surgical treatment, in order to provide more treatment options for clinical treatment of vitiligo.

【Abstract】 Atopic dermatitis （AD） is a common chronic inflammatory disease that often coexists with atopic diseases such as asthma, allergic rhinitis, and food allergies. In recent years, more and more studies have shown that AD is associated with various diseases such as cardiovascular diseases, autoimmune diseases, and mental disorders, which exacerbate the disease burden on patients with AD and severely affect their quality of life. This review summarizes AD-associated comorbidities reported in previous literature, analyzes their possible common pathogenesis, and explores potential treatments.

【Abstract】 Human interferon α1b is the first genetically engineered classⅠ drug in China, and has been approved for the treatment of melanoma and other tumors. As an adjuvant treatment for resected melanoma and a systemic treatment for advanced melanoma, human interferon α1b can effectively improve the survival of patients while maintaining a favorable safety profile. Based on clinical application experience and recent literature, the Skin Cancer Research Group, Committee on Dermatology, Chinese Association of Integrative Medicine and Melanoma Society of China Anti-Cancer Association convened experts in this field to develop this consensus, aiming to provide a reference for clinical treatment decisions regarding melanoma.

【Abstract】 Objective To evaluate the efficacy and safety of omalizumab in the treatment of chronic urticaria in children. Methods A retrospective study was conducted. Patients with chronic urticaria were collected from the Department of Dermatology, Hunan Children′s Hospital from January to December 2021, and divided into a control group and a combination group according to different medication regimens. The patients in the combination group received subcutaneous injections of omalizumab （150 mg, once every 4 weeks） combined with conventional-dosage antihistamines, while the patients in the control group were only treated with double-dosage or multiple types of antihistamines. The course of treatment was 3 to 6 months. The clinical efficacy and adverse reactions were observed at 3, 6, and 12 months after the start of treatment, and the recurrence was observed at 3 and 6 months after the end of treatment. Results A total of 46 children with chronic urticaria were collected. There were 13 males and 10 females in the combination group; they were aged from 6 to 17 years, including 16 aged from 6 to 12 years and 7 aged from 13 to 17 years; according to the total serum IgE levels before treatment, the patients in the combination group were divided into an increased IgE subgroup （11 cases） and a normal IgE subgroup （12 cases）. In the control group, there were 13 males and 10 females; they were aged from 6.33 to 16 years, including 15 aged from 6 to 12 years and 8 aged from 13 to 17 years. At 3, 6, and 12 months after the start of treatment, all the total response rates in the combination group were 86.96% （20/23）, which were all significantly higher than those in the control group （52.17% ［12/23］, 56.52% ［13/23］, 56.52% ［13/23］, P = 0.010, 0.022, 0.022, respectively）. In the combination group, the response rates at 3, 6, and 12 months after the start of treatment were all 14/16 in the children aged 6 to 12 years and 6/7 in those aged 13 to 17 years, and there were no significant differences between the two age groups （all χ2 = 0.01, all P = 0.907）; in the control group, the response rates were 5/15, 6/15 and 5/15 respectively in the children aged 6 to 12 years, which were significantly lower than those in the combination group （P = 0.002, 0.006, 0.006, respectively）. In the combination group, the response rates at 3, 6, and 12 months after the start of treatment were all 9/11 in the increased IgE subgroup and 11/12 in the normal IgE subgroup, and there were no significant differences between the two subgroups （all P = 0.484）. During the treatment, no serious adverse reactions were observed in the combination group and control group, and mild somnolence only occurred in 2 children in the control group. At 3 months after the end of treatment, there was no recurrence in 16 patients in the combination group and 2 experiencing recurrence in 6 in the control group, and the recurrence rate was lower in the combination group than in the control group （P = 0.030） at 6 months after the end of treatment, there was no recurrence in 16 patients in the combination group and 3 experiencing recurrence in 6 patients in the control group, and the recurrence rate was lower in the combination group than in the control group （P = 0.022）. Conclusion Omalizumab combined with conventional-dosage antihistamines could improve the clinical efficacy and reduce the recurrence rate in the treatment of chronic urticaria in children, with few adverse reactions.

【Abstract】 Telogen effluvium is the most common type of hair loss after coronavirus disease 2019. This review summarizes the literature on associations between coronavirus disease 2019 and telogen effluvium, as well as pathogenesis, diagnosis and treatment of telogen effluvium secondary to coronavirus disease 2019. Sharply increased stress, the body′s immune response, medications, and exacerbation of underlying diseases may be the main precipitating factors for telogen effluvium secondary to coronavirus disease 2019.

【Abstract】 Port-wine stain（PWS）is a congenital and progressive capillary malformation characterized by structural abnormalities of intradermal capillaries and postcapillary venules. The visible skin manifestations on the face and neck are often considered a disfigurement, and the accompanying social stigma often causes serious emotional and physical impact. As a new treatment for PWS, photodynamic therapy（PDT） mediated by hemoporfin, also known as hematoporphyrin monomethyl ether（HMME）, has shown good safety and efficacy, and is one of the most promising strategies for the treatment of PWS. Since 2017, HMME-PDT has been widely used for the treatment of PWS. To further standardize the clinical application of HMME-PDT, experts in the consensus group developed this consensus based on the latest research achievements and extensive discussions, so as to provide guidance for clinicians.

【Abstract】 Rosacea is a chronic recurrent inflammatory skin disease, and correct assessment of clinical symptoms and severity facilitates treatment options. This review summarizes a range of subjective, semi-subjective and objective methods currently used in the assessment of rosacea severity, in order to provide useful tools for clinical assessment of rosacea severity and give guidance on treatment modification according to the therapeutic effect.

【Abstract】 Nail dystrophy is a group of non-specific nail plate diseases with various clinical manifestations caused by multiple factors. Appropriate surgical approaches could be chosen according to different causes of nail dystrophy to improve the nail plate shape and relieve clinical symptoms. This review summarizes the progress in surgical treatment of pachyonychia congenita, congenital malalignment of the great toenail, congenital hypertrophy of the lateral nail folds of the hallux, chronic paronychia and other nail dystrophies, including resection of the nail matrix and nail bed, nail unit rotation surgery combined with wedge-shaped skin flap excision and repair, nail fold reconstruction, Swiss roll technique, etc., in order to provide a reference for clinicians to choose appropriate surgical approaches.