Association between atopic dermatitis and febrile seizure in young children Eunkyo Ha, Ju Hee Kim, Eun Lee, Won Seok Lee, Gi Chun Lee, Hakjun Kim, Boeun Han, Jeewon Shin, Seonkyeong Rhie, Man Yong Han BMC Pediatrics, 2026 Atopic dermatitis is associated with mental health and epileptic seizure in adults, which are attributed to inflammatory cytokine dysregulation, resulting in neuromodulatory dysfunction and neuronal hyperexcitability. The aim of the study is the investigation the potential association between atopic dermatitis and febrile seizure in young children. Data of children born in Korea were obtained from the National Health Insurance Service claims database, which is linked to the National Health Screening Program for Infants and Children database. We analyzed health insurance data at birth from 2008 to 2012 who were followed up until December 31, 2018. The exposure was atopic dermatitis, defined operationally in NHIS claims data as ≥ 5 L20.x diagnoses and ≥ 2 topical corticosteroid prescriptions during the study period; the primary outcome was febrile seizure (ICD-10 codes R56.00 and R56.01) occurring after the index date between 6 months and 6 years of age. The exposed cohort comprised 69,238 children, who were matched with an unexposed cohort of the same size. The median age at atopic dermatitis diagnosis was 2.5 months, and 49.5% were male. During a mean follow-up period of 4.4 ± 0.6 years, the incidence of febrile seizure in the atopic dermatitis group was approximately 8% higher than that in the control group (adjusted hazard ratio: 1.079, 95% confidence interval: 1.02–1.14). The incidence of febrile seizure was 36.5 per 10,000 person-years in the exposed cohort and 33.5 per 10,000 person-years in the unexposed cohort, yielding an absolute rate difference of 3.0 per 10,000 person-years (95% confidence interval: 1.05–4.94). This association remained consistent in propensity score–weighted analyses, across seizure-disorder subgroups, and with lag-time extensions. Atopic dermatitis was associated with a modest but statistically significant increase in the risk of febrile seizure in young children. Further studies are required to clarify the biological mechanism underlying this relationship.
Total airway mechanics and fractional exhaled nitric oxide levels of children living in banjihas (semi-basements) Ji Hee Kwak, Ju Hee Kim, Eun Kyo Ha, Hye Mi Jee, Youn Ho Shin, et al. Asian Pacific Journal of Allergy and Immunology, 2026 BACKGROUND: The ISAAC phase III study in Korea found a higher incidence of wheezing illnesses among residents in basements or semi-basements. OBJECTIVE: This study investigates the link between living in banjihas (semi-basements) and airway resistance and Th2 airway inflammation in Korean children, compared to those on higher floors. METHODS: We assessed 575 fifth- and sixth-grade students (aged 10-12) in an inner-city area of South Korea. The study utilized impulse oscillometry to measure small and total airway resistance (Rrs20-5 and Rrs0, respectively) and Fractional Exhaled Nitric Oxide (FeNO) measurements to evaluate airway inflammation. We also considered a range of biological and environmental factors, including allergen sensitization, serum 25-hydroxyvitamin D levels, and urinary metabolites like VOCs, bisphenol, and triclosan. Participants were categorized by living floors: banjihas, first-fifth floors, and sixth floors or higher. RESULTS: Twenty-five children (4.3%) lived in banjihas, 311 (54.1%) on the first to fifth floor, and 239 (41.6%) on the sixth floor or above. Despite similar levels of allergen sensitization and urinary pollutant metabolite levels across all groups, banjiha dwellers showed significantly higher total airway resistance (adjusted &1: 0.633, 95%CI: 0.156, 1.109; P = 0.009) and a greater prevalence of elevated FeNO levels (> 35 ppb) (P = 0.033). These findings persisted after adjusting for critical factors like height, gender, BMI z-score, and birth conditions. CONCLUSION: Children in banjihas exhibit elevated airway resistance and FeNO levels independently of allergen sensitization or pollution exposure, underscoring the necessity for enhanced focus on their respiratory health in such living conditions.
Croup in infancy and subsequent asthma development: is there a link? Ju Hee Kim, Ja Kyoung Kim, Jin Sung Park, Bo Eun Han, Eun Hye Lee, Eunkyo Ha, Man Yong Han, Eun Hee Chung Journal of Asthma, 2026 OBJECTIVE: Croup is a common respiratory illness in young children and usually resolves spontaneously. This study investigated whether a history of croup is associated with an increased risk of childhood asthma. METHODS: Using the Korean National Health Insurance Service database, we conducted a nationwide, population-based cohort study of children born between 2008 and 2012. Children treated for croup in an emergency department were assigned to the exposed group, and 10 age- and sex-matched children without croup were selected as controls for each case. Asthma was defined based on diagnostic codes, asthma-related medications, or asthma-related hospitalization, and asthma incidence was followed through 2021. Associations between croup and subsequent asthma were assessed using Cox proportional hazards models adjusted for demographic and perinatal factors. RESULTS: The cohort included 10,879 children with croup and 108,790 matched controls. The incidence of asthma was slightly higher in the croup group than in controls (41.8 vs. 38.6 per 1000 person-years). A history of croup was associated with a modestly increased risk of asthma (adjusted hazard ratio (aHR), 1.07; 95% confidence interval (CI), 1.02-1.13). Recurrent croup (≥2 episodes) was associated with a substantially higher asthma risk (aHR 1.41, 95% CI, 1.27-1.56), whereas a single episode was not. The association was most pronounced among children with concomitant atopic conditions. CONCLUSIONS: Recurrent croup, but not a single episode, was associated with an increased risk of subsequent asthma, suggesting that recurrent croup may be an early clinical marker of asthma susceptibility, particularly in children with coexisting atopic conditions.
Tracing neurodevelopment and growth pattern in six-year-old children with idiopathic clubfoot: a national cohort study Sung Tan Cho, Ha-Na Yoo, Simho Jeong, Ju Hee Kim, Eun Kyo Ha, Bo Eun Han, Wongthawat Liawrungrueang, Man Yong Han, Soonchul Lee BMC Musculoskeletal Disorders, 2025 STUDY DESIGN: Population-based retrospective cohort study. OBJECTIVES: The developmental impact of idiopathic clubfoot on children remains underexplored. This study investigates neurodevelopment and physical growth in children with idiopathic clubfoot up to age six. METHODS: This population-based retrospective cohort study was conducted in South Korea (2009-2019) using linked data from National Health Insurance Service. The cohort included children diagnosed with idiopathic clubfoot and 1:10 exact match of healthy control children. Neurodevelopmental assessments were conducted using the validated Korean Developmental Screening Test, which covers six domains: gross motor skills, fine motor skills, cognition, language, social skills, and self-regulation, for children aged 42-71 months. Secondary outcomes measured were height and body mass index (BMI) Z-score during the same period. RESULTS: The cohort comprised 484 children with idiopathic clubfoot and 4,840 matched healthy control children. Children with clubfoot had a higher rate of premature birth (7.44% vs. 3.66%, p < 0.0001) and lower birth weight (3.08 ± 0.59 kg vs. 3.20 ± 0.46 kg, p < 0.0001) compared to the healthy control children. In-depth evaluation of all six neurodevelopmental domains showed significant differences in children with clubfoot (overall aOR, 3.671; 95% CI, 2.463-5.471). Children with clubfoot showed a significant height delay (Z score, -1.63 below), but no BMI difference was noted. CONCLUSIONS: Children with idiopathic clubfoot demonstrated increased risk of neurodevelopmental delays and reduced height compared to their peers. These findings underscore the importance of early recognition and ongoing monitoring by parents and pediatricians.
Lifetime Age-Stratified Associations of Comorbidities in Chronic Urticaria: A Claims-Based Study of 35,907 Cases Eun Kyo Ha, Ju Hee Kim, Jeewon Shin, Won Seok Lee, Boeun Han, Eun Lee, Seonkyeong Rhie, Dong Hyun Kim, Man Yong Han Clinical and Experimental Allergy, 2025 Chronic urticaria is a long-lasting inflammatory skin condition that presents with recurrent wheals and/or angioedema lasting more than 6 weeks [1, 2]. While its cutaneous symptoms are the most visible, chronic urticaria has been increasingly recognised as a systemic disease with potential links to multiple chronic conditions [3]. Previous studies have reported associations between chronic urticaria and allergic diseases [4], including atopic dermatitis and allergic rhinitis, as well as autoimmune diseases [5] such as autoimmune thyroiditis and rheumatoid arthritis. However, limited population-based data have evaluated the full range of comorbidities associated with chronic urticaria, particularly in an age-stratified context. To address this gap, we conducted an 18-year nationwide cohort study using a randomly selected, nationally representative sample from the Korean National Health Insurance Service (NHIS) database, which covers 97% of the population. This allows the findings to be generalisable and supports robust longitudinal analysis based on individual-level data, including demographics, ICD-10 diagnoses, procedures and prescriptions. Chronic urticaria cases were identified using validated criteria: ≥ 2 ICD-10 codes (L50.1, L50.8, L50.9) recorded at least 6 weeks apart, along with ≥ 42 days of H1-antihistamine prescriptions within 1 year (see Figure S1 in the following repository, DOI: 10.5281/zenodo.15479285). The index date was defined as the first qualifying diagnosis. Each patient with chronic urticaria was matched with 10 controls by age and sex. Controls were assigned the same index date as their matched case and excluded if they had any prior diagnosis of chronic urticaria. This 1:10 matching enhanced statistical power and reduced confounding. Comorbidities were categorised into five groups: allergic [4], autoimmune [5], chronic inflammatory [6], malignant [7] and metabolic diseases [8], defined using ICD-10 codes and prescription records. Age was stratified into four groups (0–19, 20–39, 40–59, ≥ 60 years), and socioeconomic status was assessed using income and the Area Deprivation Index (ADI). Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for season, calendar year and region. Subgroup analyses were conducted by antihistamine use duration and ADI. Individuals diagnosed with chronic urticaria during the 2002 washout year or with less than 1 year of follow-up were excluded. This study provides population-level evidence on chronic urticaria-related comorbidities across age and socioeconomic strata. We identified 35,907 patients with chronic urticaria (56.4% female; 46.9% aged 0–19 years, 63.5% aged 20–39 years, 59.6% aged 40–59 years and 57.1% aged ≥ 60 years) who were assigned at least one diagnostic label for chronic urticaria during the observation period, along with 359,070 matched controls. Over a median follow-up of 8.3 years, chronic urticaria patients showed significantly elevated risks for most of the comorbidity categories (Figure 1 and Figure S2, 10.5281/zenodo.15479285). Allergic diseases were consistently associated with chronic urticaria across all age groups (HR 1.91, 95% CI: 1.87–1.95). Autoimmune diseases were significantly associated with chronic urticaria in all age groups (HR 1.50, 95% CI: 1.44–1.57). Notably, autoimmune thyroiditis was more prominent in adults, while rheumatoid arthritis showed a strong association in the 40–59 years group. In older adults, chronic urticaria demonstrated significant associations with malignancies. Specifically, associations with thyroid and brain/meningeal cancers were elevated in the 40–59-year group, while gallbladder/pancreatic cancer, kidney/bladder cancer and leukaemia were notably increased in those aged ≥ 60 years (see Figure S3, 10.5281/zenodo.15479285). Through subgroup analysis, we examined the relationship between comorbid diseases and antihistamine prescription patterns. Longer antihistamine use, used as a proxy for persistent disease, was associated with greater significance of comorbidities across all five categories (see Table S1, 10.5281/zenodo.15479285). This suggests a potential link between disease chronicity and systemic involvement. Subgroup analyses by the Area Deprivation Index (ADI) and residential area showed no substantial effect modification, indicating that socioeconomic status did not account for the observed associations. Our study highlights that chronic urticaria is not merely a dermatologic disorder but a condition potentially intertwined with immune dysfunction and chronic systemic disease [2, 9]. The broad associations with autoimmune, inflammatory and metabolic conditions suggest shared pathogenic mechanisms, such as chronic low-grade inflammation or immune dysregulation. The elevated cancer risks, although modest, warrant attention and may reflect either increased surveillance or paraneoplastic phenomena [2]. Notably, the comorbidity burden was not confined to adults. Children and adolescents with chronic urticaria exhibited increased hazard ratios for various allergic and inflammatory diseases, indicating that systemic manifestations may begin early. These findings support the need for longitudinal monitoring and age-specific management strategies in patients with chronic urticaria. Given the chronic nature of the disease and its association with multiple health burdens, clinicians should remain vigilant for potential comorbidities throughout the disease course. This study has several strengths, including a large sample size, long follow-up duration and age-stratified analyses. The use of strict diagnostic criteria and prescription-based confirmation helps mitigate misclassification. However, limitations include the use of administrative data, which lacks clinical details such as disease severity and subtype differentiation. We were unable to distinguish chronic spontaneous urticaria from inducible types, and causality cannot be inferred from the observational design. Although we attempted to refine the case definition using prescription-based criteria, the inability to clearly differentiate chronic spontaneous urticaria from chronic inducible urticaria remains a key limitation. In conclusion, chronic urticaria is associated with a broad range of comorbid conditions across all age groups. These associations are particularly evident in patients with prolonged symptoms. As chronic urticaria prevalence continues to rise, our findings underscore the need for comprehensive, multidisciplinary care and long-term follow-up. Future research should investigate whether early intervention in chronic urticaria can mitigate the onset or severity of associated systemic diseases. Conceptualisation: M.Y.H., D.H.K.; Data curation: B.H. and M.Y.H.; Formal analysis: B.H. and M.Y.H.; Funding acquisition: S.R. and M.Y.H.; Methodology: E.K.H., B.H. and M.Y.H.; Project administration: E.K.H. and M.Y.H.; Resources: S.R. and M.Y.H.; Software: B.H. and M.Y.H.; Supervision: S.R., D.H.K. and E.K.H.; Writing: E.K.H. and M.Y.H.; Review and editing: All authors. The authors have nothing to report. This study was conducted with ethical approval from the Institutional Review Board of Kangnam Sacred Heart Hospital (IRB No: 2020-04-018). Written consent from the participants was waived as the dataset used was anonymised. The authors declare no conflicts of interest. This study was based on the National Health Claims Database established by the National Health Insurance Service (NHIS) of the Republic of Korea. The data that support the findings of this study are available from the corresponding author upon reasonable request.
Lifetime annual incidence trends in chronic urticaria: an 18-year follow-up study of 40 253 cases Eun Kyo Ha, Ju Hee Kim, Jeewon Shin, Won Seok Lee, Boeun Han, Eun Lee, Seonkyeong Rhie, Dong Hyun Kim, Man Yong Han British Journal of Dermatology, 2025 The incidence of chronic urticaria has risen significantly in Korea, particularly among children and women, as revealed by an 18-year cohort study using the Korean Health Insurance database. These findings emphasize the importance of enhanced clinical management and increased awareness of chronic urticaria’s growing impact.
Changes of Clinical Practice Patterns of Allergen Immunotherapy in Korea Hwa Young Lee, Sung-Yoon Kang, Kyunghoon Kim, Ju Hee Kim, Gwanghui Ryu, Jin-Young Min, Kyung Hee Park, So-Young Park, Myongsoon Sung, Youngsoo Lee, Eun-Ae Yang, Hye Mi Jee, Eun Kyo Ha, Yoo Seob Shin, Yong Won Lee, Eun Hee Chung, Sun Hee Choi, Young-Il Koh, Seon Tae Kim, Dong-Ho Nahm, Jung Won Park, Jung Yeon Shim, Doo Hee Han, Man Yong Han, Sang Min Lee, Jeong-Hee Choi, and Allergy Asthma and Immunology Research, 2025 This study aimed to identify recent changes of AIT treatment behaviors in real-world clinical practice using a questionnaire survey in Korea. The questionnaire on AIT prescriptions and practical experiences was distributed to all members of the Korean Academy of Asthma Allergy and Clinical Immunology in June 2022. The responses were analyzed and compared with the results from 2009 and 2017. In total, 115 responses (10.1%) were collected; 58 (50.4%) from internal medicine, 34 (29.6%) from pediatricians, and 21 (18.3%) from otolaryngologists. The prescription rate for subcutaneous immunotherapy (SCIT) was 53.8%, showing a decrease from those in 2009 and 2017; however, that for sublingual immunotherapy (SLIT) increased steadily, reaching 17.9% in 2009, 40.3% in 2017, and 46.2% in 2022. The prescription rates for asthma and atopic dermatitis increased by 4.6% and 7.9%, respectively. The most frequently prescribed allergens for SCIT in 2022 were house dust mites (32.9%), pollen (30.6%), and animal dander (28.2%), with the rate for animal dander showing a significant increase from 10.3% in 2009. Most physicians (93%) used mixed allergens for SCIT, with 42.8% using a combination of 5 or more allergens. Fifty-eight (67.4%) respondents reported cases of anaphylaxis during SCIT and 36.2% reported systemic adverse reactions during SLIT. In conclusion, SLIT prescriptions, AIT for asthma and atopic dermatitis, and AIT with animal dander increased significantly from 2009 to 2022. Serial surveys of AIT practices are helpful in identifying the changes of real-world clinical practice of AIT.
Diverse weaning foods and diet patterns at multiple time points during infancy period and their association with neurodevelopmental outcomes in 6-year-old children Ju Hee Kim, Eun Kyo Ha, Gi Chun Lee, Boeun Han, Jeewon Shin, Man Yong Han, Seonkyeong Rhie European Journal of Clinical Nutrition, 2025 Background/Objectives Understanding the impact of early-life nutritional choices on neurodevelopment in children is a growing area of research. To investigate the association between dietary patterns at multiple timelines and neurodevelopmental outcomes in 6-year-old children. Subjects/Methods This administrative observational study utilized a merged data from the national health insurance database and the health screening program for children. Information on the diet patterns from infancy to 3 years of age was obtained from parent-administered questionnaires. Dietary pattern clusters of the participants were identified using Polytomous Latent Class Analysis. The outcome was neurodevelopment using the Korean Developmental Screening Test (K-DST) at the age of 6 years. Results The study identified four distinct clusters among with the 133,243 eligible children (49.6% male, birth weight 3.22 kg, head circumference 42.7 cm at 4 months). The control cluster (53.4%) exhibited a diet including breast milk feeding and a variety of dietary patterns at the age of 1 year. In contrast, cluster 1 (36.0%) showed a skewed dietary pattern at the same age. Cluster 2 (6.6%) displayed diverse dietary patterns at one year but primarily consumed formula at four months, while cluster 3 (4.0%) had reduced dietary diversity and formula feeding. Compared with the control cluster, the adjusted odds ratio for unfavorable development was 1.209 (95% CI, 1.156–1.266) in cluster 1, 1.418 (95% CI, 1.312–1.532) in cluster 2, and 1.741 (95% CI, 1.593–1.903) in cluster 3. These findings remained consistent across individual domains of the K-DST. Conclusions Dietary patterns during infancy and early childhood may be associated with neurodevelopment at the age of 6 years.
National prevalence of atopic dermatitis in Korean adolescents from 2009 to 2022 Mafaz Kattih, Hojae Lee, Hyesu Jo, Jinyoung Jeong, Hyejun Kim, Jaeyu Park, Hwi Yang, Ann Nguyen, Hyeon Jin Kim, Hyeri Lee, Minji Kim, Myeongcheol Lee, Rosie Kwon, Sunyoung Kim, Ai Koyanagi, Min Seo Kim, Masoud Rahmati, Guillermo F. López Sánchez, Elena Dragioti, Ju Hee Kim, Selin Woo, Seong H. Cho, Lee Smith, Dong Keon Yon Scientific Reports, 2024
The KAAACI Guidelines for Sublingual Immunotherapy Jin-Young Min, Hye Mi Jee, Hwa Young Lee, Sung-Yoon Kang, Kyunghoon Kim, Ju Hee Kim, Kyung Hee Park, So-Young Park, Myongsoon Sung, Youngsoo Lee, Eun-Ae Yang, Gwanghui Ryu, Eun Kyo Ha, Sang Min Lee, Yong Won Lee, Eun Hee Chung, Sun Hee Choi, Young-Il Koh, Seon Tae Kim, Dong-Ho Nahm, Jung Won Park, Jung Yeon Shim, Young Min An, Man Yong Han, Jeong-Hee Choi, Yoo Seob Shin, Doo Hee Han, and Allergy Asthma and Immunology Research, 2024
Clinical Manifestations and Genotype of Primary Ciliary Dyskinesia Diagnosed in Korea: Multicenter Study Minji Kim, Mi-Hee Lee, Soo-Jong Hong, Jinho Yu, Joongbum Cho, Dong In Suh, Hyung Young Kim, Hye-Young Kim, Sungsu Jung, Eun Lee, Sooyoung Lee, Kyunguk Jeong, Jung Yeon Shim, Jeong Hee Kim, Hai Lee Chung, Yoon Young Jang, Ji-Won Kwon, Ju-Hee Seo, Ju Hee Kim, Ji Young Ahn, Kun-Baek Song, Kyu-Sang Song, So Yeon Kim, Seon Young Kim, Hong Ryang Kil, Eun Hee Chung Allergy Asthma and Immunology Research, 2023
KAAACI Guidelines for Allergen Immunotherapy Hwa Young Lee, Sang Min Lee, Sung-Yoon Kang, Kyunghoon Kim, Ju Hee Kim, Gwanghui Ryu, Jin-Young Min, Kyung Hee Park, So-Young Park, Myongsoon Sung, Youngsoo Lee, Eun-Ae Yang, Hye Mi Jee, Eun Kyo Ha, Yoo Seob Shin, Eun Hee Chung, Sun Hee Choi, Young-Il Koh, Seon Tae Kim, Dong-Ho Nahm, Jung Won Park, Jung Yeon Shim, Young Min An, Doo Hee Han, Man Yong Han, Yong Won Lee, Jeong-Hee Choi, for the Korean Academy of Asthma Allergy, Clinical Immunology (KAAACI) Allergen Immunotherapy, Allergen Working Group Allergy Asthma and Immunology Research, 2023
