【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】 In order to promote the standardization of diagnosis and treatment of moderate to severe atopic dermatitis in China, Chinese Society of Dermatology and China Dermatologist Association organized Chinese experts to establish a clinical pathway for the diagnosis and treatment of moderate to severe atopic dermatitis, through a combined approach of literature analysis, thematic discussion, and expert consultation. Firstly, the diagnosis, assessment, screening, and examination items for atopic dermatitis, as well as entry criteria for clinical pathway were described; secondly, the treatment principles, regimens and drugs for moderate to severe atopic dermatitis were elaborated, so were the efficacy assessment, follow-up and evaluation indicators, patient education and guidance, standards for pathway completion, pathway variation and its cause analysis; it was suggested that the course of induction treatment should not be less than 3 months, and the plan of maintenance treatment should be set for at least 3 - 6 months after the efficacy of induction treatment was achieved; finally, the management process and the clinical pathway form for the diagnosis and treatment of moderate to severe atopic dermatitis were listed in the appendixes.

【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 in the elderly （> 60 years old） differs from that in children and adults in terms of demographical characteristics, pathogenesis, clinical manifestations and complications, and special considerations are needed for its diagnosis and treatment. Thus, the Immunology Group of the Chinese Society of Dermatology developed an expert consensus on the diagnosis and treatment of atopic dermatitis in the elderly, aiming to standardize and guide the effective management of elderly patients with 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】 Chronic prurigo is an independent chronic inflammatory skin disease, and complex underlying etiologies or comorbidities may exist in patients. Diagnosis of chronic prurigo requires a systematic process, including identifying core symptoms, taking a comprehensive medical history, performing physical examination, completing necessary laboratory or imaging tests, and assessing disease severity. Treatments of chronic prurigo include management of possible causes and comorbidities, and stepwise control of pruritus. This review mainly summarizes clinical diagnosis, classification and treatment of chronic prurigo.

【Abstract】 Cutaneous adverse reactions are common during anti-tumor therapy, which not only greatly affect patients′ quality of life, but may also cause discontinuation and dose reduction of anti-tumor therapy. With the increasing diversity of anti-tumor drugs, cutaneous adverse reactions have become more complex and challenging for clinicians. In view of this, the Shanghai Society of Dermatology and Venereology and Shanghai Society of Target Molecular Oncology, Shanghai Medical Association organized experts to discuss and sort out existing relevant clinical evidence to develop an expert consensus. This consensus summarizes cutaneous adverse reactions to anti-tumor drugs, such as cytotoxic chemotherapy drugs, molecular targeted drugs, and immune checkpoint inhibitors, and proposes prevention and management measures for common cutaneous adverse reactions, aiming to provide standardized guidance for clinicians and nurses in the fields of oncology and dermatology in clinical practice.

【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】 Chronic actinic dermatitis is a photosensitive dermatosis commonly occurring in middle-aged and elderly males, clinically characterized by eczematous lesions on the sun-exposed skin. The diagnosis mainly relies on clinical manifestations and photobiological tests. The key to treatment is avoidance of sunlight exposure and removal of photosensitizers, and other treatments include topical drugs, physical therapy, systemic drugs, etc. Based on recent research advances in chronic actinic dermatitis in China and other countries, the Dermatology Professional Committee of Chinese Research Hospital Society and the China Dermatologist Association organized experts in the field of photodermatology to discuss the causes, pathogenesis, clinical manifestations, diagnosis, differential diagnosis, treatment and prognosis of chronic actinic dermatitis in clinical practice, and to develop an expert consensus on the diagnosis and treatment of chronic actinic dermatitis （2023）, which provided a scientific and authoritative reference for the diagnosis and management of chronic actinic dermatitis.

【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】 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】 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】 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】 Frontal fibrosing alopecia is a primary lymphocytic cicatricial alopecia, and generally considered to be a subtype of lichen planopilaris due to similar histopathological changes. Its etiology is still unclear. With the deepening of research on this disease, more and more cases of frontal fibrosing alopecia have been reported in China and other countries. This review summarizes research progress in pathogenesis, clinical and pathological characteristics, and treatment of frontal fibrosing alopecia.

【Abstract】 Interleukin-17 （IL-17） has been proved to be closely associated with the pathogenesis of various inflammatory skin diseases. Its main source is Th17 cells, whose differentiation is evoked by interleukin-23 （IL-23）. Therefore, the IL-23/Th17 axis is an emerging target for the treatment of inflammatory skin diseases. IL-17 antagonists, IL-23 antagonists and IL-12/23 antagonists have shown satisfactory efficacy and safety in the treatment of psoriasis, atopic dermatitis, hidradenitis suppurativa, pityriasis rubra pilaris and SAPHO syndrome in latest clinical trials. Accordingly, this review mainly summarizes progress in molecular signaling pathways in and pathophysiological basis of the IL-23/Th17 axis in the occurrence of inflammatory skin diseases, as well as clinical application of different biological agents targeting this axis.

【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】 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】 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】 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】 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】 Interface dermatitis refers to a group of skin diseases in which inflammation mainly involves the dermo-epidermal junction, including lichen planus, lupus erythematosus, dermatomyositis, lichen sclerosus, lichen nitidus, lichen striatus, erythema multiforme, bullous pemphigoid, Riehl melanosis, poikiloderma, large-plaque parapsoriasis/mycosis fungoides, etc. Interface dermatitis shows characteristic reflectance confocal microscopic features. This review summarizes reflectance confocal microscopic characteristics of interface dermatitis and recent progress in the application of reflectance confocal microscopy in its auxiliary diagnosis.

【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】 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】 Kaposi′s sarcoma is a multicentric sarcoma of endothelial cell origin, which mainly occurs on the skin and can involve the mucosa, lymph nodes and internal organs. The occurrence of Kaposi′s sarcoma is associated with human herpesvirus 8 infection, immunity, environment, genetics, and other factors. The incidence of Kaposi′s sarcoma has shown an increasing trend in recent years. The China Dermatologist Association and Dermatology Professional Committee of Chinese Research Hospital Society organized relevant experts to develop an expert consensus on the diagnosis and treatment of Kaposi′s sarcoma in China based on a review of Chinese and international literature including guidelines and combined with the current status of its diagnosis and treatment in China, aiming to provide a reference for clinicians to standardize its diagnosis and treatment.

【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】 Objective To evaluate the disease burden （number of patients and characteristics of disease） and unmet medical needs （current status and inadequacy of medical treatment） in Chinese patients with moderate-to-severe psoriasis （msPsO）. Methods High-quality real-world evidence on Chinese msPsO patients was sorted and reviewed in the MEDLINE, EMBASE, Web of Science, Wanfang, VIP, and CNKI databases from January 1st, 2012 to August 31st, 2022. The disease burden as well as challenges and shortcomings of systemic therapeutic drugs were analyzed in Chinese msPsO patients. Results In China, msPsO patients made up a high proportion （67.0%） of psoriasis patients, and the number was estimated to be about 5 million. They were characterized by high severity of disease （the mean psoriasis area and severity index score of 16.3 points）, large affected body surface area （22.1%）, a high proportion of scalp psoriasis （63.1%）, and high prevalence of comorbid metabolic syndrome （21.2%）. Current evidence suggested that traditional oral therapeutic drugs were still challenged by limited efficacy and a high risk of adverse reactions, whereas patients showed relatively high rates （58.7% - 91.2%） of 75% improvement in psoriasis area and severity index （PASI75） response after 12-week treatment with biological agents; however, discontinuation of biological therapies was common after 52 weeks （15.0% - 54.2%）, and the main reason was the lack of efficacy （8.3% - 31.4%）, followed by economic pressures （5.6% - 19.0%） and adverse reactions （2.3% - 4.8%）. Conclusion The number of Chinese msPsO patients is relatively large, and there is an urgent need for new effective, durable, safe, and easily usable drugs to meet the demand for long-term therapeutic management of msPsO.

【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】 Tumor heterogeneity is one of the important characteristics of melanoma. Single-cell RNA sequencing can not only further reveal the heterogeneity of melanoma cells, but also has unique advantages in analyzing the occurrence and development of melanoma, finding new targets for immunotherapy and uncovering mechanisms of drug resistance. This review summarizes the application of single-cell transcriptome sequencing in melanoma research.

【Abstract】 This review summarizes reports on viral infection?induced psoriasis, as well as research advances in mechanisms underlying antiviral innate immunity and acquired immunity in psoriasis, and discusses the important role of viral infection in the occurrence and development of psoriasis, providing new ideas for effective prevention and treatment of psoriasis.

【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】 Pediatric melanoma occurs rarely, and the pathogenesis is different in different subtypes. The diagnostic criteria for adult melanoma may not be fully applicable to pediatric patients due to atypical clinical manifestations of some tumors. Surgery is the first?line treatment, and the accurate resection margin could be smaller than that in adults. In recent years, immunotherapy and targeted therapy for melanoma have developed rapidly, but very few drugs have been approved for children. Although there have been few large?sample studies on the treatment of pediatric melanoma, the application of related drugs has been reported in literature. This review summarizes progress in the pathogenesis, clinical manifestations and treatment of pediatric melanoma, in order to provide a reference for the diagnosis and treatment of pediatric melanoma.