Genome-wide Association Study of Susceptibility Loci for Self-Reported Atopic Dermatitis and Allergic Rhinitis in the Korean Population.

BACKGROUND: Allergic diseases include atopic dermatitis (AD) and allergic rhinitis (AR), which are chronic, relapsing inflammatory disorders of the skin or mucosa that usually accompany immunoglobulin E-mediated immune responses. They are complex, multifactorial diseases with an etiology involving interactions between genetic and environmental factors. OBJECTIVE: We performed a genome-wide association study (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with allergic diseases in the Korean population. METHODS: A total of 8,840 samples were obtained from the Korean Association Resource Consortium dataset of the Korean Genome and Epidemiology Study Ansan-Anseong cohort. The allergic disease phenotype was determined based on self-reported physician diagnoses. After quality control, 8,823 subjects with 877,242 variants remained for the final analysis. The GWAS was performed using logistic regression analysis in an additive model adjusted for age and sex. RESULTS: A total of 636 patients with allergic disease and 8,176 controls were analyzed. Three SNPs were associated with allergic disease at a level of genome-wide suggestive significance (p<1.0×10-5) in the Korean population: rs7275360, located in neural cell adhesion molecule 2; rs698195; and rs3750552, located in family with sequence similarity 189, member A2. These polymorphisms were on chromosomes 21q21.1, 7q31.1, and 9q21.12, respectively. CONCLUSION: We identified 3 novel SNPs significantly associated with allergic diseases in the Korean population. Further research is required to confirm the association between these novel SNPs and allergic disease in the Korean population and in other ethnicities.

Artificial intelligence-based prescription of personalized scalp cosmetics improved the scalp condition: efficacy results from 100 participants.

Background: Scalp-related symptoms such as dandruff and itching are common with diverse underlying etiologies. We previously proposed a novel classification and scoring system for scalp conditions, called the scalp photographic index (SPI); it grades five scalp features using trichoscopic images with good reliability. However, it requires trained evaluators.Aim: To develop artificial intelligence (AI) algorithms for assessment of scalp conditions and to assess the feasibility of AI-based recommendations on personalized scalp cosmetics.Methods: Using EfficientNet, convolutional neural network (CNN) models (SPI-AI) ofeach scalp feature were established. 101,027 magnified scalp images graded according to the SPI scoring were used for training, validation, and testing the model Adults with scalp discomfort were prescribed shampoos and scalp serums personalized according to their SPI-AI-defined scalp types. Using the SPI, the scalp conditions were evaluated at baseline and at weeks 4, 8, and 12 of treatment.Results: The accuracies of the SPI-AI for dryness, oiliness, erythema, folliculitis, and dandruff were 91.3%, 90.5%, 89.6%, 87.3%, and 95.2%, respectively. Overall, 100 individuals completed the 4-week study; 43 of these participated in an extension study until week 12. The total SPI score decreased from 32.70 ± 7.40 at baseline to 15.97 ± 4.68 at week 4 (p < 0.001). The efficacy was maintained throughout 12 weeks.Conclusions: SPI-AI accurately assessed the scalp condition. AI-based prescription of tailored scalp cosmetics could significantly improve scalp health.

Automated mass screening and association rules analysis for comorbidities of psoriasis: A population-based case-control study.

Patients with psoriasis frequently have comorbidities, which are linked to higher mortality rates. An in-depth investigation of comorbidities and their effects on health can help improve the management of patients with psoriasis. We conducted a comprehensive and unbiased investigation of comorbidities in patients with psoriasis and explored the pattern of association between comorbidities. A nationwide population-based study included 384 914 patients with psoriasis and 384 914 matched controls between 2011 and 2021. We used automated mass screening of all diagnostic codes to identify psoriasis-associated comorbidities and applied association rule analysis to explore the patterns of comorbidity associations in patients with psoriasis. Patients with psoriasis had an increased risk of autoimmunity-related diseases such as inflammatory arthritis, Crohn's disease, type 1 diabetes, and acute myocardial infarction. The comorbidities of patients with psoriasis with a history of cardiovascular events demonstrated strong interrelationships with other cardiovascular risk factors including type 2 diabetes mellitus, essential hypertension, and dyslipidemia. We also found comorbidities, such as malignant skin tumors and kidney and liver diseases, which could have adverse effects of anti-psoriasis therapy. In contrast, patients with psoriasis showed a decreased association with upper respiratory tract infection. Our results imply that comorbidities in patients with psoriasis are associated with the systemic inflammation of psoriasis and the detrimental effects of its treatment. Furthermore, we found patterns of associations between the cardiovascular risk factors and psoriasis. Mass screening and association analyses using large-scale databases can be used to investigate impartially the comorbidities of psoriasis and other diseases.

Clinical Response to Low-dose Omalizumab Treatment in Chronic Spontaneous Urticaria: A Retrospective Study of 179 Patients.

Omalizumab is effective in chronic spontaneous urticaria unresponsive to antihistamines. Of the licensed dosing schedules, Korean patients prefer a low dose, of 150 mg/month, for financial reasons. However, real-world experiences of low-dose omalizumab consumption have not been reported. The aim of this retrospective study was to assess the treatment outcomes and long-term clinical course of patients with chronic spontaneous urticaria who were treated with low-dose omalizumab. The study included 179 patients aged ≥ 20 years who were treated with omalizumab 150 mg/month for ≥ 12 weeks. Baseline disease activity was mild, moderate, and severe in 54.7%, 35.2%, and 10.1% of patients, respectively. A complete response was observed in 133 patients at 12 weeks, among whom 88 patients showed early responses within 4 weeks. Overall, 158 patients finally achieved a complete response. Multivariate analyses revealed that baseline disease activity is more likely to be mild in patients who experience early and final complete responses. The absence of atopic comorbidities correlated with an early response. Smoking was associated with a final complete response. This study shows that low-dose omalizumab provides favourable treatment outcomes in antihistamine-refractory chronic spontaneous urticaria. Disease severity, atopic comorbidity, and smoking may be predictive factors for studying the response to omalizumab.

Needleless laser injector versus needle injection for skin enhancement and rejuvenation effect of dermal filler.

BACKGROUND AND OBJECTIVES: A needleless laser-induced microjet injector is a novel transdermal drug delivery system that can rapidly inject a very small and precise drug dose into the skin with minimal pain and downtime. In this study, we aimed to compare the laser-induced microjet injection versus needle injection of polylactic acid/hyaluronic acid filler for skin enhancement and rejuvenation. PATIENTS AND METHODS: A 24-week prospective, single-center, assessor-blinded, randomized, split-face study was conducted. The enrolled patients underwent one treatment session of dermal filler injection using a laser-induced microjet injector on one half of the face or a traditional needle injection on the other half of the face. Evaluation was conducted at baseline before treatment and at 4, 12, and 24 weeks after treatment. RESULTS: A single treatment of filler injection with a laser-induced microjet injector resulted in similar improvements in skin hydration and elasticity as a single treatment of filler injection by using manual needle injection, with reduced pain, side effects, and decreased treatment time. CONCLUSIONS: Laser-induced microjet injector enabled not only the application of a controlled dose and filler depth but also even distribution, improved clinical efficacy, reduced pain and side effects, and sufficient time for clinicians to perform treatment.

Association between cardio-cerebrovascular disease and systemic antipsoriatic therapy in psoriasis patients using population-based data: A nested case-control study.

The effect of antipsoriatic therapy on cardio-cerebrovascular disease (CCVD) is not well described. Thus, we performed a population-based nested case-control study to investigate the effect of systemic antipsoriatic therapy on CCVD in psoriasis patients. Using nationwide cohort data from the Korean National Health Insurance Claims database, newly diagnosed psoriasis patients were identified. Among the enrolled participants, postenrollment development of CCVD events (ischemic heart disease, myocardial infarction, cerebral infarction, and cerebral hemorrhage) was investigated. To evaluate the effect of systemic antipsoriatic therapy on CCVD risk, we calculated the proportion of the treatment period with systemic antipsoriatic therapy during the study period (PTP [%]: the sum of all systemic antipsoriatic therapy durations divided by total observation period). Among 251 813 participants, 6262 experienced CCVD events during the study period (CCVD group). Controls included 245 551 patients without CCVD history during the study period (non-CCVD group). The non-CCVD group had greater PTP than the CCVD group (CCVD 2.12 ± 7.92, non-CCVD 2.64 ± 9.64; P < 0.001). In multiple logistic regression analysis, PTP was inversely associated with the CCVD risk after adjusting for age, sex, diabetes, hypertension, and dyslipidemia. A 10% increase in PTP reduced CCVD risk by 0.96 (95% confidence interval 0.93 to 0.99). Reduced CCVD risk was robust for both conventional antipsoriatic therapy and biologics. Our study found that systemic antipsoriatic therapy use was inversely associated with CCVD risk in psoriasis patients. These findings suggested that systemic antipsoriatic therapy could reduce CCVD development in patients with psoriasis.

Structure-Guided Development of Bivalent Aptamers Blocking SARS-CoV-2 Infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused devastation to human society through its high virulence, infectivity, and genomic mutations, which reduced the efficacy of vaccines. Here, we report the development of aptamers that effectively interfere with SARS-CoV-2 infection by targeting its spike protein, which plays a pivotal role in host cell entry of the virus through interaction with the viral receptor angiotensin-converting enzyme 2 (ACE2). To develop highly effective aptamers and to understand their mechanism in inhibiting viral infection, we determined the three-dimensional (3D) structures of aptamer/receptor-binding domain (RBD) complexes using cryogenic electron microscopy (cryo-EM). Moreover, we developed bivalent aptamers targeting two distinct regions of the RBD in the spike protein that directly interact with ACE2. One aptamer interferes with the binding of ACE2 by blocking the ACE2-binding site in RBD, and the other aptamer allosterically inhibits ACE2 by binding to a distinct face of RBD. Using the 3D structures of aptamer-RBD complexes, we minimized and optimized these aptamers. By combining the optimized aptamers, we developed a bivalent aptamer that showed a stronger inhibitory effect on virus infection than the component aptamers. This study confirms that the structure-based aptamer-design approach has a high potential in developing antiviral drugs against SARS-CoV-2 and other viruses.

Risk of uveitis in patients with psoriasis in Korea: A nationwide population-based cohort study.

BACKGROUND: Evidence for the association between psoriasis and uveitis according to the severity of psoriasis including psoriatic arthritis (PsA) and type of uveitis is lacking, and there are no data on the frequency or timing of recurrence of uveitis in patients with psoriasis. OBJECTIVES: We aimed to evaluate the risk of first occurrence and recurrence of uveitis in patients with psoriasis in the Korean population. We further evaluated the risk of uveitis according to the severity of psoriasis, comorbidity of PsA and location of uveitis. METHODS: In a nationwide retrospective cohort study, we compared 317,940 adult patients who had psoriasis with 635,880 matched controls. Incidence rates (IRs) and estimated IR ratios of the first occurrence and recurrence of uveitis were calculated using survival analysis and Poisson regression, respectively. RESULTS: The rate of uveitis incidence and uveitis recurrence in patients with psoriasis was 1.18 and 2.31 per 1000 person-years, respectively. Compared to the controls, the IR ratios of development and recurrence of uveitis in patients with psoriasis were 1.14 (95% CI 1.08, 1.2) and 1.16 (95% CI 1.12, 1.21), respectively. The recurrence rate of uveitis was highest within 3 years after the onset of psoriasis. The corresponding IR ratios for uveitis recurrence in patients with mild psoriasis, severe psoriasis and PsA were 1.11 (1.06, 1.16), 1.24 (1.16, 1.33) and 1.49 (1.31, 1.7), respectively. Patients with psoriasis had an increased risk of recurrence of anterior uveitis, and patients with both psoriasis and PsA had an increased risk of recurrence of both anterior-uveitis and panuveitis. CONCLUSIONS: Patients with psoriasis had a higher risk of both development and recurrence of uveitis, especially with severe psoriasis and PsA. The timing of uveitis recurrence was related to the onset of psoriasis, and patients who had psoriasis with PsA had an increased risk of vision-threatening panuveitis.

A Randomized Split-Face Study of Photodynamic Therapy With St. John's Wort and Indole-3-Acetic Acid for the Treatment of Acne.

BACKGROUND: St. John's wort (SJW) contains hypericin, a powerful photosensitizer with antimicrobial and anti-inflammatory activities. OBJECTIVE: To compare the efficacy and safety of SJW-photodynamic therapy (PDT) with that of indole-3-acetic acid (IAA)-PDT for the treatment of acne and investigate the skin rejuvenating effects of SJW-PDT. MATERIALS AND METHODS: In vitro experiments were conducted to examine the generation of reactive oxygen species and the antimicrobial effects of SJW-PDT. In the prospective, double-blind, split-face, randomized study, 31 patients with facial acne were treated with SJW or IAA with simultaneous illumination of red light and green light. RESULTS: SJW produces free radicals with visible light irradiation, and the growth of Cutibacterium acnes and Staphylococcus aureus is significantly suppressed. One week after the last treatment, the acne lesion counts were significantly decreased in both groups (56.5% reduction in SJW, p < .001 vs 57.0% in IAA, p < .001). Significant reductions in sebum secretion, erythema index, roughness, and wrinkles were observed in both groups after the treatment. No side effects were observed. CONCLUSION: SJW-PDT is a simple, safe, and effective treatment option for acne that is also beneficial for skin rejuvenation.

Efficacy and Safety of the Micro-insulated Needle Radiofrequency Device for Reduction of Submental Fat.

BACKGROUND: Recently, it has been reported that a micro-insulated needle radiofrequency (RF) system is effective at achieving subcutaneous fat reduction; however, no study has yet applied this technique to reduce submental fat. OBJECTIVE: To evaluate the efficacy and safety of a fractional RF device with a micro-insulated needle to reduce submental fat. MATERIALS AND METHODS: In this prospective, single-blinded, pre-post comparative study, 24 adults with excess submental fat were treated once using a micro-insulated needle RF device. Outcomes included efficacy (submental fat rating by an independent investigator, fat volume quantified with a 3-dimensional camera, and patient satisfaction), assessed 1 and 2 months after the procedure, and safety (adverse events), assessed throughout the study. RESULTS: The patients' Physician-Assisted Submental Fat Rating Scale score significantly decreased after 1 month and further decreased after 2 months. The average volume of submental fat was significantly decreased after 2 months (20.44 ± 5.53 cc to 16.41 ± 4.58 cc, p < .001). Patient satisfaction was high. Transient and mild local skin reactions without long-term sequelae were observed in 4 patients. CONCLUSION: The micro-insulated needle RF device is beneficial for the reduction of submental fat and has tolerable safety profiles. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05517824.

Evaluation of the area subscore of the Palmoplantar Pustulosis Area and Severity Index using an attention U-net deep learning algorithm.

Palmoplantar pustulosis (PPP) is a variant of pustular psoriasis involving the palms and soles. The severity of PPP is usually evaluated using the Palmoplantar Pustulosis Area and Severity Index (PPPASI). Among the components of the PPPASI, the area of the involved lesion is evaluated differently by raters, who generally make a rough estimate using the eye and not through a specific calculation. To overcome inconsistent evaluation of the area subscore of PPPASI by human raters, we developed and validated deep-learning-based algorithms to enable automated and reliable assessment of the area involved in PPP to provide clinical advantages. In this study, we developed a dataset of 611 images of the palms and soles of 153 patients with PPP. We evaluated the area of the lesion by dividing the number of pixels in the area involved in PPP by the number of pixels in the area of the palms or soles. Using attention U-net, we developed two convolutional neural network (CNN) models that can evaluate the percentage of the affected area (%) and subsequently assign a score ranging from 0 to 6. The area subscore of PPPASI evaluated by the deep-learning algorithm was same or differed by 1-point from the subscore of ground truth in 98.8% of the images. The intraclass correlation coefficient between the CNN and ground truth was 0.879, indicating good agreement. The accuracy and mean absolute error of the model were 66.7% and 0.344, respectively. In a Bland-Altman plot, most of the differences in the percentage of the affected area lay between the 95% confidence interval with a mean difference of 0 and a standard deviation of 0.2. The deep-learning algorithm can provide several clinical advantages by objectively evaluating the components of the PPPASI without concern for disagreement between clinicians. The algorithms further enable cumulative clinical data acquisition related to PPP severity.

Development of a new classification and scoring system for scalp conditions: Scalp Photographic Index (SPI).

BACKGROUND AND OBJECTIVES: There has been no validated tool for objectively quantifying the overall condition and characteristics of the scalp. This study aimed to establish and validate a new classification and scoring system for evaluating scalp conditions. METHODS: The Scalp Photographic Index (SPI) using a trichoscope grades five features of scalp conditions (dryness, oiliness, erythema, folliculitis, and dandruff) on a score of 0-3. To evaluate the validity of SPI, SPI grading was performed by three experts on the scalps of 100 subjects along with a dermatologist's assessment of the scalps and a scalp-related symptom survey. For reliability assessment, 20 healthcare providers performed SPI grading for the 95 selected photographs of the scalp. RESULTS: SPI grading and the dermatologist's scalp assessment showed good correlations for all five scalp features. Warmth showed a significant correlation with all features of SPI and the subjects' perception of a scalp pimple had a significant positive correlation with the folliculitis feature. SPI grading demonstrated good reliability with excellent internal consistency (Cronbach's α = 0.90) and strong inter- and intra-rater reliability (Kendall's W = 0.84, ICC(3,1)=0.94). CONCLUSIONS: SPI is an objective, reproducible, and validated numeric system for classifying and scoring scalp conditions.

Early Postoperative Injections of Polydeoxyribonucleotide Prevent Hypertrophic Scarring After Thyroidectomy: A Randomized Controlled Trial.

Objective: Polydeoxyribonucleotide (PDRN) is known to enhance wound healing, but there has been no clinical trial investigating the effect of PDRN on scar prevention in surgical wounds. This study aimed to evaluate the efficacy of PDRN administration in preventing postoperative scars. Approach: In this randomized controlled trial (NCT05149118), 44 patients who underwent open thyroidectomy were randomly assigned to the PDRN treatment or untreated control group. Only patients in the treatment group received two consecutive injections of PDRN 1 and 2 days after surgery. The modified Vancouver Scar Scale (mVSS), patients' subjective symptoms, erythema index (EI), melanin index (MI), and scar height were assessed 3 months after surgery. Results: Patients in the treatment group had lower mVSS scores (1.619 ± 1.244 vs. 2.500 ± 1.540, respectively; p = 0.059) and a significantly lower vascularity subscore (0.476 ± 0.512 vs. 0.900 ± 0.447, respectively; p = 0.010) than those in the control group at the 3-month follow-up. Compared with the control group, the level of subjective symptoms, EI, and scar height were all significantly lowered in the PDRN injection group. No specific side effects related to PDRN injection were observed. Innovation: This is the first clinical study that demonstrated that PDRN injections rapidly decreased postsurgical wound erythema and as a result, significantly reduced both excessive scar formation and accompanying symptoms. Conclusion: Early postoperative injection of PDRN is an effective and safe treatment to prevent hypertrophic scars and improve scar outcomes.

Topical methylene blue nanoformulation for the photodynamic therapy of acne vulgaris.

Acne vulgaris is a common skin disease caused by multifactorial reasons involving excessive sebum secretion and inflammation by Cutibacterium acnes (C. acnes). Various conventional therapies are available for the treatment of acne vulgaris; however, topical photodynamic therapy (PDT) has attracted much attention because of its great potential for sebum-reducing, anti-inflammatory, and antimicrobial activities. Although 5-aminolevulinic acid (ALA) has been broadly used as a photosensitizer for topical PDT, it has several limitations such as long incubation time, pain, and post-inflammatory hyperpigmentation. Here, we report a biocompatible nanoformulation consisting of methylene blue and salicylic acid (MBSD), as a potent PDT and acne therapeutics, enclosed within oleic acid. Photoactivated MBSD showed antimicrobial activity against C. acnes along with long-term stability. When 24 patients with acne were treated with MBSD and light irradiation 5 times at 1-week intervals, MBSD-based PDT exhibited a remarkable reduction in acne lesions and sebum production. In addition, the therapeutic procedure was painless and safe, without any adverse events. Therefore, MBSD is a promising topical PDT agent for biocompatible, safe, and effective acne treatment.

Reflectance Confocal Microscopy in the Diagnosis of Onychomycosis: A Systematic Review.

Accurately diagnosing onychomycosis is vital, as therapy is time-consuming and accompanied by multiple adverse effects. Reflectance confocal microscopy (RCM), in contrast to traditional mycological testing, is a noninvasive, point-of-care tool that can rapidly identify fungal lesions. This systematic review aims to understand the utility of RCM in evaluating onychomycosis and follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic search of four databases was conducted. A total of five articles-three prospective cohort studies and two case reports-which reported RCM findings in nails clinically suspicious for onychomycosis were analyzed. Fungal hyphae or spores were visualized on RCM in 67 (81.7%) of the 82 mycologically confirmed cases of onychomycosis. Terms used to describe hyphae included bright, linear, lengthy, thready-like, branching and filamentous. Spores were described as bright, roundish structures with high reflection. The three cohort studies demonstrated RCM had a sensitivity of 52.9-91.7, a specificity of 57.58-90.2%, a positive predictive value of 61.1-88.6% and a negative predictive value of 68.0-90.5%. In conclusion, existing studies demonstrate how RCM can assist the diagnosis of onychomycosis at the bedside. Larger studies incorporating multiple testing modalities to confirm the diagnosis of onychomycosis are warranted to further explore the diagnostic utility of RCM.

Association between the cumulative dose of cyclosporine and liver enzyme abnormalities in dermatology patients managed with a low-dose regimen.

Cyclosporine (CsA) is an immunosuppressive agent that specifically inhibits T cell-related immune responses. There is little evidence regarding the association between low-dose CsA administration and abnormal hepatic function in dermatology patients. This study aimed to examine the association between the cumulative dose of CsA and liver enzyme abnormalities obtained from peripheral blood tests in patients with skin diseases. A retrospective single-center study of 697 patients who were prescribed CsA for skin disease in the outpatient dermatology clinic between 2015 and 2019 were performed. Multiple logistic regression with confounder adjustment was performed to assess the association between the cumulative dose of CsA and liver enzyme abnormalities. Compared to patients with the lowest cumulative dose of CsA (˂7.0 g), patients with the highest cumulative dose of CsA (≥30.6 g) were significantly associated with an increased likelihood of developing liver enzyme abnormalities (odds ratio [OR] = 1.96; 95% confidence interval [CI] = 1.02-3.79). In the stratified analysis, patients with the highest cumulative dose of CsA (≥30.6 g) were significantly associated with a 1.5-or higher alanine aminotransferase elevation from baseline (OR = 2.26, CI = 1.08-4.73). Patients prescribed long-term, low-dose CsA up to a high cumulative dose (≥30.6 g) may be associated with an increased risk of developing liver enzyme abnormalities. However, these liver enzyme elevations were not severe in magnitude and were reversible.

The degradation of performance of a state-of-the-art skin image classifier when applied to patient-driven internet search.

Model Dermatology ( https://modelderm.com ; Build2021) is a publicly testable neural network that can classify 184 skin disorders. We aimed to investigate whether our algorithm can classify clinical images of an Internet community along with tertiary care center datasets. Consecutive images from an Internet skin cancer community ('RD' dataset, 1,282 images posted between 25 January 2020 to 30 July 2021; https://reddit.com/r/melanoma ) were analyzed retrospectively, along with hospital datasets (Edinburgh dataset, 1,300 images; SNU dataset, 2,101 images; TeleDerm dataset, 340 consecutive images). The algorithm's performance was equivalent to that of dermatologists in the curated clinical datasets (Edinburgh and SNU datasets). However, its performance deteriorated in the RD and TeleDerm datasets because of insufficient image quality and the presence of out-of-distribution disorders, respectively. For the RD dataset, the algorithm's Top-1/3 accuracy (39.2%/67.2%) and AUC (0.800) were equivalent to that of general physicians (36.8%/52.9%). It was more accurate than that of the laypersons using random Internet searches (19.2%/24.4%). The Top-1/3 accuracy was affected by inadequate image quality (adequate = 43.2%/71.3% versus inadequate = 32.9%/60.8%), whereas participant performance did not deteriorate (adequate = 35.8%/52.7% vs. inadequate = 38.4%/53.3%). In this report, the algorithm performance was significantly affected by the change of the intended settings, which implies that AI algorithms at dermatologist-level, in-distribution setting, may not be able to show the same level of performance in with out-of-distribution settings.

Risk of Psoriasis in Postgastrectomy Gastric Cancer Survivors: A Nationwide Population-Based Cohort Study.

Background: Although patients with psoriasis have an increased risk of cancers, little is known about the risk of psoriasis in cancer patients. Objective: We aimed to comparatively analyze the incidence and risk factors of psoriasis in gastric cancer patients who underwent gastrectomy and in the general population. Methods: A nationwide retrospective cohort of 52,608 gastric cancer survivors (2007~2015) was compared to 123,438 matched controls from the general population to estimate the incidence and hazard ratio (HR) of new-onset psoriasis. We also calculated the HRs for psoriasis according to adjuvant cancer treatment, obesity, and vitamin B12 supplementation in gastric cancer survivors. Results: During a mean follow-up of 6.85 years, 645 of the 52,608 gastric cancer patients developed psoriasis, while 1,806 in the 123,438 matched control group developed psoriasis. Gastric cancer patients had a decreased risk of psoriasis (HR, 0.86; 95% confidence interval, 0.79~0.94), especially those who underwent subtotal gastrectomy. We found that vitamin B12 supplementation for more than 3 years had an additive effect on decreasing the risk of psoriasis in gastric cancer patients who underwent subtotal gastrectomy. Total gastrectomy, radio/chemotherapy, and obesity did not affect the risk of psoriasis in gastric cancer survivors. Conclusion: The incidence of psoriasis is slightly lower in gastric cancer survivors than in the general population. Our results suggest that the development of psoriasis may be reduced by removing the source of systemic inflammation caused by Helicobacter pylori infection through subtotal gastrectomy in gastric cancer survivors.

Clinical characteristics of pustulotic arthro-osteitis in Korea.

Pustulotic arthro-osteitis (PAO) has been studied primarily in Japan. However, there is a lack of research regarding its clinical features among large populations in other countries and it is often believed to be similar to psoriatic arthritis (PsA). Although the association between psoriasis (PsO) and palmoplantar pustulosis (PPP) is debatable, differences in the clinical characteristics between PsA and PAO might support the notion that PsO and PPP are distinct entities. This study aimed to investigate the clinical characteristics of PAO in Korean patients and to compare them with those of PsA. We retrospectively reviewed the medical records of patients diagnosed with PPP, PAO, and PsA. Among 266 patients with PPP, 13.2% had PAO. Unlike Japanese patients with PAO, Korean patients had a relatively lower involvement of the chest wall. PAO patients demonstrated lower age of onset, higher proportion of females, and higher severity of cutaneous eruptions compared to PPP patients without PAO, but the differences were not statistically significant. Female predominance was prominent in PAO compared to PsA. Cutaneous eruptions occurred earlier than joint symptoms in 83.5% of the patients with PsA and in 42.9% of the patients with PAO. PAO involved axial joints more frequently compared to PsA, especially the chest wall and spine. PsA mainly involved the peripheral joints, especially the metacarpophalangeal joints and distal interphalangeal joints of the hands and feet. In conclusion, PAO and PsA exhibited different demographics and locations of joint involvement, supporting the notion that PPP and PsO are separate disorders. Many PAO patients presented with joint symptoms before the appearance of skin eruptions, underlining the important role of dermatologists in recognizing PAO among PPP patients. Physicians should be aware of the characteristics of PAO while treating patients with PPP.