Background: Psoriasis is a persistent systemic inflammatory condition mediated by the interleukin (IL)-23/IL-17 signaling pathway. Existing murine models, including imiquimod (IMQ)-applied wild-type (WT) mice, may not reflect chronicity and systemic comorbidities of psoriasis, particularly gut-related manifestations linked to the gut–skin axis. Objective: To establish a murine model that more accurately reflects chronic psoriasis, its systemic comorbidities, and associated gut environment alterations. Methods: C57BL/6 IL-10-deficient (IL-10 knockout [KO]) and WT mice received topical IMQ or vehicle for 6 weeks. Subsequently, tissue samples from skin, colon, joints, kidneys, liver, abdominal aortas, lymph nodes, and spleens, as well as fecal and blood samples, were collected for histopathologic, immunologic, gut environment analysis. Results: IMQ-treated IL-10 KO mice developed prolonged psoriatic inflammatory responses with increased epidermal thickness and higher infiltration of CD45+, myeloperoxidase+, and IL-17+ cells. They also exhibited early-onset, severe colitis with marked weight loss, shortened colon length, and elevated colitis severity scores. While IMQ induced systemic inflammation in multiple organs, IL-10 KO mice did not show more severe joint, liver, or kidney involvement than WT mice. Elevated serum tumor necrosis factor alpha and plasminogen activator inhibitor-1 levels, increased heart/body weight ratio, enhanced gut permeability, and distinct gut microbiota profiles were observed in IL-10 KO mice. Conclusion The 6-week IMQ-applied IL-10 KO model may better reflect chronic and severe psoriasis with gut-related comorbidities, offering a valuable platform to investigate the gut–skin axis.

Background: Observational studies have suggested associations between dietary polyunsaturated fatty acids (PUFAs) and cancer risk; however, causal inference regarding skin cancer remains limited due to potential recall bias, confounding, and reverse causation. Objective: This study aimed to evaluate the causal association between genetically predicted circulating PUFA levels and the risk of skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. Methods: We conducted a 2-sample Mendelian randomization (MR) study using genome-wide association study summary statistics from the UK Biobank (PUFAs, n=115,006) and the FinnGen consortium (BCC, n=26,272; SCC, n=4,663; melanoma, n=5,753). Genetic instruments were derived for omega-3, docosahexaenoic acid, omega-6, linoleic acid, and the omega-6:3 ratio.Multiple MR methods—including inverse-variance weighted, MR-Egger, weighted median, weighted mode, and MR-PRESSO—were applied to test for consistency and assess pleiotropy and heterogeneity. Results: A higher genetically predicted linoleic acid to total fatty acid ratio was associated with a significantly lower risk of BCC and SCC. Conversely, higher genetically proxied serum omega-3 levels were associated with increased risks of BCC, SCC, and melanoma. The risk effect on SCC was attenuated upon exclusion of rs174528, a variant in the fatty acid desaturase 1 (FADS1) gene, suggesting a role for endogenous PUFA metabolism in carcinogenesis. Conclusion This MR analysis supports a causal role of circulating PUFAs in skin cancer development and highlights the importance of FADS-mediated endogenous PUFA metabolism. These findings provide novel insights into the genetic and metabolic underpinnings of skin cancer susceptibility.

Background: A set of criteria for severity classification is essential in alopecia areata (AA). Currently, no guidelines are universally accepted for defining AA severity. Objective: This study aimed to establish a set of consensus criteria for classifying the severity of and identifying treatment refractoriness in AA. Methods: A preliminary draft of the definition for moderate-to-severe AA was crafted based on available evidence, and members of the Korean Hair Research Society (KHRS) subsequently endorsed the recommendation through an online survey. Results: In the first Delphi round, consensus was attained on 15 questions. After refining certain items in the second round, consensus was achieved on 23 out of 26 questions. The KHRS first defined AA severity using the severity of alopecia tool (SALT). SALT ≥50 was defined as severe, 20≤ SALT <50 as moderate, and SALT <20 as mild. Moderate AA was considered severe if it meets one or more of the following criteria: dermatology life quality index >10, presence of accompanying eyebrow or eyelash loss, positive hair loss activity, or treatment-refractory AA. Conclusion These consensus criteria can help clinicians accurately diagnose AA, provide appropriate treatment, and monitor its progression.

Background: Alopecia areata (AA) is characterized by hair loss on the scalp and body, significantly impacting patients’ quality of life based on its severity. Objective: This study aims to identify crucial factors influencing the perception of severe AA from the patients’ viewpoint. Methods: A web-based survey was conducted among AA patients attending dermatology departments at 21 university hospitals in Korea. The survey comprised 17 criteria, exploring both clinical characteristics of AA patients and subjective determinants of disease severity. Results: A total of 791 AA patients and their caregivers participated in the survey. Approximately 30% of respondents developed AA during childhood, with 43.5% experiencing chronic courses lasting over 3 years. Half of the participants exhibited more than 20% scalp hair loss, and 42% reported additional hair loss on other body parts, such as eyelashes and nose hair.Most respondents agreed that patients with ≥20% scalp hair loss should be categorized as having severe AA. They also identified longer disease duration, involvement of non-scalp body hair, treatment refractoriness, and social or mental impairment requiring medical intervention as factors indicating increased disease severity. Conclusion This survey underscores the significant impact of AA on patients’ quality of life and highlights existing unmet needs in current treatment modalities.

Background: Alopecia areata (AA) is a chronic disease with an unpredictable course and can have a severe psychological impact on an individual. Objective: To provide evidence and consensus-based statements regarding the treatment of patients with AA in Korea. Methods: We searched for relevant studies from inception to May 2021 regarding the systemic treatment of AA. Evidence-based recommendations were also prepared. The evidence for each statement was graded and classified according to the strength of the recommendations. Hair experts from the Korean Hair Research Society (KHRS) voted on the statement, and an agreement of 75% or greater was considered as having reached consensus. Results: Current evidence supports the efficacy of systemic corticosteroids, oral cyclosporine monotherapy or combination with systemic corticosteroids, and oral Janus kinase inhibitors in severe AA patients. Systemic steroids may be considered for pediatric patients with severe AA. A consensus was achieved in three out of nine (33.3%), and one out of three (33.3%) statements pertaining to systemic treatment in adult and pediatric AA, respectively. Conclusion The present study produced up-to-date, evidence-based treatment guidelines for AA associated with the consensus obtained by experts based on the Korean healthcare system.

Background: Alopecia areata (AA) is a chronic disease with an unpredictable disease course and severe psychological impact. Objective: To provide evidence- and consensus-based insights regarding the treatment of patients with AA in Korea. Methods: We searched for relevant studies on the topical and device-based treatment of AA in the literature from inception until May 2021. Evidence-based recommendations were also prepared. The evidence for each statement was graded and classified according to the strength of the recommendations. Hair experts from the Korean Hair Research Society (KHRS) voted on the statements, and an agreement of 75% or greater was considered as consensus. Results: Currently, there remains a scarcity of topical treatments, which is supported by robust evidence from a number of high-quality randomized controlled trials. Current evidence supports the efficacy of topical corticosteroids, corticosteroid intralesional injection, and contact immunotherapy in AA patients. Topical corticosteroids and contact immunotherapy are recommended for pediatric AA. A consensus was achieved in 6 out of 14 (42.8%), and 1 out of 5 (20.0%) statements pertaining to topical and device-based treatments in AA, respectively. The expert consensus was from a single country, and the study may not cover all the treatments used. Conclusion The present study provides up-to-date, evidence-based treatment guidelines for AA based on the consensus reached among experts after considering regional healthcare circumstances, adding diversity to the previous guidelines.

Background: To determine the risk of pregnancy complications and adverse offspring outcomes in Korean women with rheumatic diseases (RDs). Methods: Women aged 20–44 years with pregnancies ending in delivery were identified from the National Health Insurance Service-National Health Information Database (2009–2016).Women with RD including systemic lupus erythematosus (SLE), seropositive rheumatoid arthritis (SPRA), and ankylosing spondylitis (AS) (n = 4,284) were age-matched with controls (n = 26,023). Outcome variables included threatened abortion (TA), preterm birth (PB), preeclampsia/eclampsia (PE/E), intrauterine growth retardation (IGR), urinary tract infection, low birth weight (LBW) offsprings, and offspring death within 1 year of birth. Results: Women with RDs had increased risks for cesarean section delivery (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.4–1.6), TA (OR, 1.4; 95% CI, 1.2–1.5), PB (OR, 2.4; 95% CI, 1.9–3.2), PE/E (OR, 4.4; 95% CI, 3.3–5.9), and IGR (OR, 2.4; 95% CI, 2.0–3.1) than the controls. The risk of pregnancy complications was increased in SLE and SPRA pregnancies but not in AS pregnancies. Offsprings of women with RDs had an increased risk of LBW (OR, 4.0; 95% CI, 3.2–4.9). The offspring mortality rate within 1 year of birth was higher in women with RDs (6.2/10,000 persons) than in the controls (4.9/10,000 persons). Conclusion Women with RDs are at a risk of developing pregnancy complications, and the risk of LBW offsprings and offspring death within 1 year of birth is increased in these women.Therefore, this population requires special attention during their childbearing years.

Background/Aims: We aimed to estimate the prevalence of comorbidities and medication use in Korean women with rheumatic diseases (RDs) during their childbearing years. Methods: We included women aged 20 to 44 years with seropositive rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and ankylosing spondylitis (AS) (n = 41,547) and age-matched women without seropositive RA, SLE, and AS (n = 208,941) from the National Health Insurance Service-National Health Information Database (2009 to 2016). The prevalence of hypertension (HTN), hyperlipidemia (HLD), diabetes mellitus (DM), and cancer and the use of nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids (CSs), and disease-modifying anti-rheumatic drugs (DMARDs) were estimated. Results: Women of childbearing age with RDs were more likely to have at least one of the measured comorbidities than the controls (odds ratio [OR], 3.0; 95% confidence interval [CI], 2.9 to 3.1). The OR (95% CI) was 2.9 (2.8 to 3.0) for HTN, 2.8 (2.7 to 2.9) for HLD, 1.4 (1.4 to 1.5) for DM, and 1.3 (1.3 to 1.4) for cancer. The SLE group had the highest prevalence and odds of all four measured comorbidities. Almost all (97.9%) women of childbearing age with RDs were taking RD-related medications (NSAIDs, 81.6%; CSs, 77.8%; DMARDs, 87.3%). The RD group was 13.8 times more likely to take NSAIDs and 68.2 times more likely to take CSs than the controls. Use of NSAIDs was more prevalent in RA and AS than SLE, whereas use of CSs and DMARDs was more prevalent in RA and SLE than AS. Conclusions Korean women with RDs have a greater burden of comorbidities and medication use during their childbearing years than women without RDs of the same age.