【Abstract】 Nowadays, various countries have developed guidelines/consensus on the diagnosis and treatment of alopecia areata. Differences between these guidelines/consensus may reflect differences in backgrounds, research status, medical resources and clinical traditions among countries. This review compares Chinese and international guidelines/consensus on the diagnosis and treatment of alopecia areata in the past three years, and analyzes the epidemiology, etiology, diagnosis, severity assessment methods and treatment of alopecia areata, so as to provide a reference for standardized and individualized diagnosis and treatment of alopecia areata in China.

【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】 The application of moisturizers and emollients is an important method for protecting or repairing skin barriers, maintaining skin health, and coping with skin diseases. In order to standardize and rationalize the application of moisturizers and emollients, the China Dermatologist Association convened Chinese experts in this field to conduct sessions of in-depth discussions based on up-to-date Chinese and international research outcomes, and reached a consensus on the efficacy, composition selection, application indications, application methods and adverse reactions of moisturizers and emollients, as well as considerations during their use.

【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 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】 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】 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】 Metformin, the first-line treatment of type 2 diabetes, has been also increasingly used in the treatment of some skin diseases, such as psoriasis. This review summarizes therapeutic mechanisms of and clinical research progress in metformin in the treatment of psoriasis, aiming to provide ideas and methods for the treatment of psoriasis, especially psoriasis complicated by metabolic diseases.

【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】 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】 In recent years, new therapeutic targets for bullous pemphigoid (BP) have continued to emerge, and new biologic agents targeting pathogenic antibodies, complements, T helper type 2 (Th2) and Th17 cytokines in BP have also successively entered clinical trials, e.g., the CD20-targeting antibody rituximab and the IgE-targeting antibody omalizumab have been applied in clinical practice and have benefited some patients with refractory BP. This review summarizes the literature and clinical trials related to biologic agents as the treatment strategy for BP, analyzes and discusses clinical application of new biological agents in BP, in order to provide new ideas for the treatment of refractory BP.

【Abstract】 Gardner-Diamond syndrome is a rare skin disease characterized by recrudescent, spontaneous, tender ecchymoses, and mostly affects psychologically disturbed adult women. The positive autoerythrocyte sensitization test has noticeable diagnostic significance. Currently, there is no specific therapy for Gardner-Diamond syndrome. This review summarizes advances in the pathogenesis, clinical features, diagnosis and treatment of this disease.

【Abstract】 Androgens are important sex hormones in the body, and are involved in the occurrence and development of various skin diseases, such as acne, androgenetic alopecia, hirsutism. Anti-androgen drugs can act on different sites in the androgen synthesis and functional pathways to antagonize the effects of androgens, and can be used in the alleviation and treatment of related diseases. In recent years, some research progress has been made in the treatment of skin diseases with anti-androgen drugs. For example, clascoterone is a first-in-class topical drug in the treatment of acne in the last 40 years, dutasteride can be applied in male patients aged over 20 years with androgenetic alopecia, and topical finasteride is markedly effective for the treatment of androgenetic alopecia, as well as idiopathic hirsutism in females. This review summarizes research progress in anti-androgen drugs in the treatment of skin diseases in recent years.

【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】 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】 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】 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】 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】 Autoinflammatory diseases （AIDs） are a group of abnormal inflammatory diseases mediated by innate immune cells with a certain hereditary susceptibility, including monogenic AIDs and polygenic AIDs. AIDs are characterized by various clinical manifestations, periodic attacks and intermittent symptom relief, multiple systems are often involved, and skin is one of the predominantly involved organs. Due to genetic diversity and uncertainty in AIDs, gene-based classification is unhelpful in clinical recognitoin and selection of therapeutic strategies. With in-depth study of the pathogenesis of AIDs, researchers have found overlapping inflammatory pathways in AIDs sharing common skin lesions, which may be treated with similar strategies. This review describes classification of AIDs according to features of skin lesions, summarizes commonalities in their immune mechanisms and histopathological features, and discusses possible effective treatment regimens and interventions, in order to facilitate the clinical diagnosis and treatment.

【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】 Hidradenitis suppurativa（HS）/acne inversa（AI） is a chronic, recurrent and inflammatory skin disease caused by follicular atresia with varying clinical manifestations, and there is no unified classification criteria for it in China and other countries. Based on its clinical characteristics, gene mutations and their correlations, researchers have enriched the subtype classification of HS/AI. This review summarizes recent advances in clinical phenotypes and genotypes of HS/AI as well as their relationships, in order to help clinicians better understand the disease, and provide a theoretical basis for correct diagnosis and individualized treatment strategies.

【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】 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】 In order to further standardize the diagnosis and treatment of atopic dermatitis by health-care professionals, as well as to enhance the awareness of atopic dermatitis among patients and promote doctor-patient communication, Chinese Society of Dermatology and China Dermatologist Association jointly initiated the development of guidelines on the diagnosis and treatment of atopic dermatitis （specialist version, general practitioner version and patient version）. The development working group had planned the development process of the 3 versions of guidelines with reference to relevant development manuals and methodological articles. It is also intended to expound the details of registration, working group establishment, clinical question collection, evidence search and grading, recommendation formation and consensus through this protocol, aiming to enhance the transparency of guideline development.

【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 pathogenesis of atopic dermatitis is complex, and mainly related to genetic background, environmental stimuli, epidermal barrier defects, immune disorders, and other factors. Using Th2-type inflammatory cytokines and the JAK-STAT pathway as therapeutic targets has become a hotspot in drug development for atopic dermatitis. By now, multiple monoclonal antibodies and small-molecule drugs have been successfully used in the treatment of atopic dermatitis, marking that the treatment of atopic dermatitis has entered the era of precision therapy and targeted therapy.

【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】 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】 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.