Background: Atopic dermatitis (AD) is a common skin disease with a wide range of symptoms. Due to the rapidly changing treatment landscape, regular updates to clinical guidelines are needed. Objective: This study aimed to update the guidelines for the treatment of AD to reflect recent therapeutic advances and evidence-based recommendations. Methods: The Patient characteristics, type of Intervention, Control, and Outcome framework was used to determine 48 questions related to AD management. Evidence was graded, recommendations were determined, and, after 2 voting rounds among the Korean Atopic Dermatitis Association (KADA) council members, consensus was achieved. Results: This guideline provides treatment guidance on advanced systemic treatment modalities for AD. In particular, the guideline offers up-to-date treatment recommendations for biologics and Janus-kinase inhibitors used in the treatment of patients with moderate to severe AD.It also provides guidance on other therapies for AD, along with tailored recommendations for children, adolescents, the elderly, and pregnant or breastfeeding women. Conclusion KADA’s updated AD treatment guidelines incorporate the latest evidence and expert opinion to provide a comprehensive approach to AD treatment. The guidelines will help clinicians optimize patient-specific therapies.

Background: Atopic dermatitis (AD) is a common skin disease with a wide range of symptoms. Due to the rapidly changing treatment landscape, regular updates to clinical guidelines are needed. Objective: This study aimed to update the guidelines for the treatment of AD to reflect recent therapeutic advances and evidence-based practices. Methods: The Patient characteristics, type of Intervention, Control, and Outcome framework was used to determine 48 questions related to AD management. Evidence was graded, recommendations were determined, and, after 2 voting rounds among the Korean Atopic Dermatitis Association (KADA) council members, consensus was achieved. Results: The guidelines provide detailed recommendations on foundational therapies, including the use of moisturizers, cleansing and bathing practices, allergen avoidance, and patient education. Guidance on topical therapies, such as topical corticosteroids and calcineurin inhibitors, is also provided to help manage inflammation and maintain skin barrier function in patients with AD. Additionally, recommendations on conventional systemic therapies, including corticosteroids, cyclosporine, and methotrexate, are provided for managing moderate to severe AD. Conclusion KADA’s updated AD guidelines offer clinicians evidence-based strategies focused on basic therapies, topical therapies, and conventional systemic therapies, equipping them to enhance quality of care and improve patient outcomes in AD management.

Oral corticosteroids (OCS) are frequently used during pregnancy, but patterns of their usage and indications are understudied. We described OCS utilization among pregnant women in South Korea using the Health Insurance Review and Assessment database, 2010–2021. Among 4,574,294 pregnancies, 6.2% (n = 283,001) were exposed to OCS, with the annual prevalence increasing from 4.98% in 2010 to 6.65% in 2021. Methylprednisolone and prednisolone accounted for 90% of OCS use during pregnancy, and the median duration of prescriptions was four days. Respiratory and skin diseases were the most common indications, and prescriptions for pregnancy-associated conditions increased notably after 2017, coinciding with insurance coverage for infertility treatments. OCS prescriptions declined during the first trimester and increased near delivery, suggesting discontinuation upon pregnancy recognition. Our findings highlight the common and increasing use of OCS during pregnancy, mainly for acute conditions, underscoring the need for further research on their safety in pregnant populations.

Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

Background: This study aimed to estimate the association between mRNA coronavirus disease 2019 (COVID-19) vaccine exposure during pregnancy and the risks of preterm birth and congenital malformations leveraging a national population data. Methods: This retrospective cohort study utilized national data from the National Health Insurance System, linking maternal and infant records with COVID-19 vaccination registries.Newborns with congenital malformations were identified using diagnosis codes. The analysis included women aged 20–49 who gave live births between February 2022 and December 2022. Odds ratios (ORs) for preterm birth and any congenital malformation per COVID-19 vaccination during pregnancy compared to 1:4 matched unvaccinated controls, adjusted for maternal age, residential area, employment, income, disability, month of conception, prepregnancy obesity, smoking, and severe acute respiratory syndrome coronavirus 2 infection prior to pregnancy, were calculated. We compared the risk of two outcomes between BNT162b2 and mRNA-1273. Results: Among 106,692 women who gave birth during the study period, 8,966 (8.4%) received a COVID-19 vaccination during pregnancy. Of the newborns, 7,039 (6.6%) were preterm births and 7,658 (7.2%) had congenital malformations. COVID-19 vaccination during pregnancy was associated with a comparable risk of preterm birth (OR, 1.03; 95% confidence interval [CI], 0.77–1.36) and a similar risk of congenital malformations (0.90; 95% CI, 0.72–1.12) compared to non-vaccinees. The ORs of preterm birth (1.02; 95% CI, 0.77–1.36) and congenital malformation (0.91; 95% CI, 0.73–1.14) for mRNA-1273 were comparable to those for BNT162b2. Conclusion COVID-19 vaccines during pregnancy poses no increased risk of preterm birth and congenital malformations compared to those not exposed to the vaccine, with similar risk levels observed between the two mRNA vaccines. This finding provides additional evidence supporting the safety of COVID-19 vaccines.

Oral corticosteroids (OCS) are frequently used during pregnancy, but patterns of their usage and indications are understudied. We described OCS utilization among pregnant women in South Korea using the Health Insurance Review and Assessment database, 2010–2021. Among 4,574,294 pregnancies, 6.2% (n = 283,001) were exposed to OCS, with the annual prevalence increasing from 4.98% in 2010 to 6.65% in 2021. Methylprednisolone and prednisolone accounted for 90% of OCS use during pregnancy, and the median duration of prescriptions was four days. Respiratory and skin diseases were the most common indications, and prescriptions for pregnancy-associated conditions increased notably after 2017, coinciding with insurance coverage for infertility treatments. OCS prescriptions declined during the first trimester and increased near delivery, suggesting discontinuation upon pregnancy recognition. Our findings highlight the common and increasing use of OCS during pregnancy, mainly for acute conditions, underscoring the need for further research on their safety in pregnant populations.

Background: Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established. Methods: We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition. Results: Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17–1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis. Conclusion The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

Background: This study aimed to estimate the association between mRNA coronavirus disease 2019 (COVID-19) vaccine exposure during pregnancy and the risks of preterm birth and congenital malformations leveraging a national population data. Methods: This retrospective cohort study utilized national data from the National Health Insurance System, linking maternal and infant records with COVID-19 vaccination registries.Newborns with congenital malformations were identified using diagnosis codes. The analysis included women aged 20–49 who gave live births between February 2022 and December 2022. Odds ratios (ORs) for preterm birth and any congenital malformation per COVID-19 vaccination during pregnancy compared to 1:4 matched unvaccinated controls, adjusted for maternal age, residential area, employment, income, disability, month of conception, prepregnancy obesity, smoking, and severe acute respiratory syndrome coronavirus 2 infection prior to pregnancy, were calculated. We compared the risk of two outcomes between BNT162b2 and mRNA-1273. Results: Among 106,692 women who gave birth during the study period, 8,966 (8.4%) received a COVID-19 vaccination during pregnancy. Of the newborns, 7,039 (6.6%) were preterm births and 7,658 (7.2%) had congenital malformations. COVID-19 vaccination during pregnancy was associated with a comparable risk of preterm birth (OR, 1.03; 95% confidence interval [CI], 0.77–1.36) and a similar risk of congenital malformations (0.90; 95% CI, 0.72–1.12) compared to non-vaccinees. The ORs of preterm birth (1.02; 95% CI, 0.77–1.36) and congenital malformation (0.91; 95% CI, 0.73–1.14) for mRNA-1273 were comparable to those for BNT162b2. Conclusion COVID-19 vaccines during pregnancy poses no increased risk of preterm birth and congenital malformations compared to those not exposed to the vaccine, with similar risk levels observed between the two mRNA vaccines. This finding provides additional evidence supporting the safety of COVID-19 vaccines.