Eun Hee Chung

Croup is a common acute respiratory illness in early childhood, characterized by upper airway obstruction with barking cough, hoarseness, and stridor. It most frequently affects children between 6 ...

Intussusception is a common cause of acute abdominal pain among children presenting to emergency departments, but it is rare in adults, with distinct clinical and epidemiological patterns. However, large-scale comparative data are scarce, and the impact of infectious disease remains poorly understood. We analyzed nationwide emergency department data from South Korea (2019–2023) to compare cross-age clinical characteristics and investigate temporal trends associated with infectious disease incidence, using COVID-19 social distancing as a natural experiment. Among 14,723 cases, 80.8% were pediatric patients, peaking at ages 1–4, while adult cases were evenly distributed. Children presented to higher-level centers, whereas adults required hospitalization with higher clinical acuity. Vomiting and hematochezia predominated in pediatric patients, while abdominal pain and nonspecific symptoms like asthenia and dyspnea were more common in adults. During COVID-19 distancing, pediatric intussusception declined significantly, while adult cases remained stable. Correlation analysis revealed stronger associations of pediatric intussusception with respiratory viruses, particularly adenovirus and rhinovirus, than with enteric pathogens. Causal mediation analysis confirmed that respiratory viruses accounted for 65.6% of the pandemic-associated reduction, with adenovirus (68.3%) and rhinovirus (62.8%) contributing most. These findings highlight age-dependent differences and suggest temporal associations between respiratory viral infections and pediatric intussusception.

Lee HY, et al. Allergy Asthma Immunol Res. 2025 Mar;17(2):271-284. https://doi.org/10.4168/aair.2025.17.2.271

Chung J, et al. Allergy Asthma Immunol Res. 2025 Jan;17(1):77-93. https://doi.org/10.4168/aair.2025.17.1.77

Introductions: Primary ciliary dyskinesia(PCD) is a rare genetic disease that is diagnosed based on clinical findings, transmission electron microscopy(TEM), genetic testing, nasal nitric oxide test(nNO), high-speed video microscopy analysis, and functional analysis of ciliary movement. According to PCD diagnostic standards, the nNO test is less than 77 nL/min using a chemiluminescence analyzer, but this machine is expensive and difficult to use in actual clinical practice. Aims: In this study, we sought toinvestigate the diagnostic cut off value of the portable nNO device in a group of patients diagnosed with PCD and a control group. Materials and Methods: In patients diagnosed with PCD, nNO testing was performed using the NIOX VEROⓇ device using tidal breathing. Subjects were tested at least twice to compare the PCD patient group and control group. Results: There were a total of 8 PCD patients diagnosed, the nNO test result was 47.9±31.2 ppb (4-127ppb). The healthy control group was 15 people, and the nNO test result was 484.8±225.8 ppb (253-1127). There were a total of 10 people in the allergic disease group, the nNO test result was an average of 455±205.6 ppb (226-909) (P<0.001). The maximum point of the youden index (sensitivity +specificity-), which reflects the sum of sensitivity and specificity, was 177 ppb, and the youden index was 0.944. In the ROC curve showing the relationship between PCD diagnosis and nNO value, the AUC was 0.973. Conclusions: The portable nNO test can be useful in diagnosing PCD, and a diagnostic standard (cut-off) for the nNO test using an electrochemical device with high sensitivity and specificity will be needed.

Min JY, et al. Allergy Asthma Immunol Res. 2024 Jan;16(1):9-21. https://doi.org/10.4168/aair.2024.16.1.9

Background: Human coronaviruses (HCoV) cause mild upper respiratory infections; however, in 2019, a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged, causing an acute respiratory disease pandemic. Coronaviruses exhibit marked epidemiological and clinical differences.Purpose: This study compared the clinical, laboratory, and radiographic findings of children infected with SARS-CoV-2 versus HCoV.Methods: SARS-CoV-2 data were obtained from the Korea Disease Control and Prevention Agency (KDCA) registry and 4 dedicated coronavirus disease 2019 (COVID-19) hospitals. Medical records of children admitted with a single HCoV infection from January 2015 to March 2020 were collected from 10 secondary/tertiary hospitals. Clinical data included age, sex, underlying disease, symptoms, test results, imaging findings, treatment, and length of hospital stay.Results: We compared the clinical characteristics of children infected with HCoV (n=475) to those of children infected with SARS-CoV-2 (272 from KDCA, 218 from COVID-19 hospitals). HCoV patients were younger than KDCA patients (older than 9 years:3.6% vs. 75.7%; P<0.001) and patients at COVID-19 hospitals (2.0±2.9 vs 11.3±5.3; P<0.001). Patients with SARS-CoV-2 infection had a lower rate of fever (26.6% vs. 66.7%; P<0.001) and fewer respiratory symptoms than those with HCoV infection. Clinical severity, as determined by oxygen therapy and medication usage, was worse in children with HCoV infection. Children and adolescents with SARS-CoV-2 had less severe symptoms.Conclusion: Children and adolescents with COVID-19 had a milder clinical course and less severe disease than those with HCoV in terms of symptoms at admission, examination findings, and laboratory and radiology results.

Lee HY, et al. Allergy Asthma Immunol Res. 2023 Nov;15(6):725-756. https://doi.org/10.4168/aair.2023.15.6.725