Background: To address the public’s fear of coronavirus disease 2019 (COVID-19), understanding the clinical features of the disease is essential. However, research on the clinical features of COVID-19, including illness duration and post-acute COVID-19, in Korean pediatric patients has been limited. Therefore, this study investigated the clinical features of COVID-19 based on the medical records of pediatric patients with a history of COVID-19 who visited a single center. Methods: In total, 311 patients were included in this study. The presence and duration of 19 symptoms were examined. Additionally, clinical features were investigated by dividing the patients into different age ranges. Patients aged 6 and above were further categorized according to the presence of asthma, while adolescent patients were divided into vaccinated and unvaccinated groups. Results: Fever and cough were the most common symptoms. The mean illness duration was 2–4 days. Only 3.5% of the patients were asymptomatic. Post-acute COVID-19 was observed in 13.2% of the patients. The incidence of most symptoms tended to increase with age. Post-acute COVID-19 was observed more frequently in patients with asthma than in those without asthma. Vaccinated patients experienced less fever, vomiting, and fatigue than unvaccinated patients. Conclusions Our data suggest that most patients had mild disease lasting less than a week, and the clinical course may differ depending on the presence of asthma. The findings also indicate that vaccination may alleviate the symptoms of COVID-19 in breakthrough infections.

Objectives: This study aimed to present the Asia-Pacific consensus on long-term and sequential therapy for osteoporosis, offering evidence-based recommendations for the effective management of this chronic condition.The primary focus is on achieving optimal fracture prevention through a comprehensive, individualized approach. Methods: A panel of experts convened to develop consensus statements by synthesizing the current literature and leveraging clinical expertise. The review encompassed long-term anti-osteoporosis medication goals, first-line treatments for individuals at very high fracture risk, and the strategic integration of anabolic and anti resorptive agents in sequential therapy approaches. Results: The panelists reached a consensus on 12 statements. Key recommendations included advocating for anabolic agents as the first-line treatment for individuals at very high fracture risk and transitioning to anti resorptive agents following the completion of anabolic therapy. Anabolic therapy remains an option for in dividuals experiencing new fractures or persistent high fracture risk despite antiresorptive treatment. In cases of inadequate response, the consensus recommended considering a switch to more potent medications. The consensus also addressed the management of medication-related complications, proposing alternatives instead of discontinuation of treatment. Conclusions This consensus provides a comprehensive, cost-effective strategy for fracture prevention with an emphasis on shared decision-making and the incorporation of country-specific case management systems, such as fracture liaison services. It serves as a valuable guide for healthcare professionals in the Asia-Pacific region, contributing to the ongoing evolution of osteoporosis management.

Purpose: We investigated young children who developed bronchiolitis obliterans (BO) without preceding severe lower respiratory tract infection (LRTI). Methods: Twenty patients referred for chronic respiratory symptoms and diagnosed with BO were enrolled and divided into 2 age groups: group 1 ( < 2 years, n = 12) and group 2 ( ≥ 2, < 6 years, n = 8). A diagnosis of BO was made based on clinical and radiologic findings: (1) persistent cough or abnormal breath sounds which were not responsive to any treatment for more than 6 weeks; and (2) mosaic perfusion on high-resolution computed tomography. None of the subjects had experienced LRTI since birth, and those who had any underlying problems were excluded. The clinical characteristics and disease course were examined retrospectively. Results: Mean age of the patients was 6.8 months and 3.4 years in group 1 and 2, respectively. All patients presented with chronic cough and the most common type of cough was mixed (wet and dry), 67% in group 1 and 50% in group 2. Persistent stridor was the major respiratory sign in group 1 (67%), but 63% of group 2 patients showed no abnormal breath sounds. Chest x-ray finding was nonspecific in 75% each of both groups. The respiratory symptoms and signs resolved rapidly in most patients treated with pulse corticosteroid therapy. Bronchial hyperresponsiveness and decreased forced expiratory volume in 1 second were observed in 3 of group 2 children at age 6, during the follow-up. Conclusion Our study shows that BO could develop without preceding severe LRTI. It also suggests that BO should be considered in the infants with persistent stridor accompanied by chronic cough.

Purpose: Mycoplasma pneumoniae pneumonia (MP) is a major cause of community-acquired pneumonia (CAP) in children and is associated with extrapulmonary manifestations (EPM). The incidence and risk factors for EPM in children are unknown. Methods: This was a retrospective study involving 65,243 pediatric patients with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Medical records were reviewed to collect information regarding the clinical characteristics, radiological results, and laboratory findings. Logistic regression with multivariate analysis was performed to evaluate the risk factors associated with EPM in MP. Results: The incidence of EPM was 23.9%, including elevation of liver enzymes (18.1%), mucocutaneous manifestations (4.4%), proteinuria (4.1%), cardiovascular and neurological manifestations (0.4%), hematologic manifestations (0.2%), and arthritis (0.2%). Statistical analysis showed that mucocutaneous manifestations significantly increased with elevated alanine aminotransferase (adjusted odds ratio [aOR], 3.623; 95% confidence interval [CI], 1.933-6.790) and atopic sensitization (aOR, 2.973; 95% CI, 1.615–5.475) and decreased with respiratory virus coinfection (aOR, 0.273; 95% CI, 0.084–0.887). Elevated liver enzymes were significantly associated with elevated lactate dehydrogenase (aOR, 3.055; 95% CI, 2.257–4.137), presence of pleural effusion (aOR, 2.635; 95% CI, 1.767–3.930), and proteinuria with respiratory virus coinfection (aOR, 2.245; 95% CI, 1.113–4.527). Conclusion Approximately 24% of pediatric patients with MP had various EPM. As the risk factors associated with each EPM were different, it is necessary to evaluate the various clinical aspects and findings of MP to predict and prepare for the occurrence of EPM.

Purpose: Survivors of preterm birth are at high risk of chronic pulmonary disease. We examined lung function in the school-age children born preterm and investigated the relationship between lung function and clinical parameters. Methods: Thirty children born preterm were enrolled and divided into 2 groups: 14 very preterm (< 32-week gestational age [GA]) and 16 moderate-to-late preterm (32- to 36-week GA). Pulmonary function tests (PFTs) were performed repeatedly during schoolage and PFT parameters were compared with age-matched controls. The relationship between PFT and clinical parameters was also studied. Results: PFT parameters in the very preterm group were persistently reduced compared with age-matched controls (P< 0.05). Half of the children had been diagnosed with asthma at the visit for the first PFT. Seventy-seven percent of patients in the very preterm group had bronchial hyperresposiveness. Birth weight, duration of oxygen therapy and mechanical ventilation in the neonatal intensive care unit, and body weight at age 1 were associated with forced expiratory volume in 1 second (FEV 1), forced vital capacity (FVC), or forced expiratory flow between 25% and 75% of expired vital capacity (FEF 25%–75%) z-scores. Multiple regression analysis revealed that body weight at age 1 was an independent predictor of FEV 1 and FVC z-scores, and duration of oxygen therapy was independently associated with FEF 25%–75% z-scores (P< 0.01 for all). Conclusion No catch-up in lung function was observed in school-age children born very preterm. Lower body weight at age 1 might be an independent risk factor for reduced FEV 1 and FVC, whereas long-term oxygen therapy might be associated with reduced FEF 25%–75%

Purpose: Cluster analysis on pediatric asthma identifying a cluster characterized by obesity, females, and puberty showed that obesity is an independent risk factor for severe asthma in this cluster. In the present study, we aimed to investigate the effect of overweight/obesity on lung function and asthma severity in prepubertal asthmatic children. Methods: One hundred fifty-five prepubertal children (aged 6–10) with asthma were enrolled and divided into 2 groups: the overweight/obese group (body mass index [BMI] ≥ 85th percentile, n = 44) and the normal BMI group ( < 85th percentile, n = 111). We reviewed their medical records and analyzed whether there were any differences in clinical features, lung function and degree of bronchial hyperresponsiveness (BHR) between the 2 groups. The clinical factors associated with asthma severity were also investigated. Results: There was no difference in clinical features between the 2 groups. Pulmonary function tests showed that only forced vital capacity in 1 second/forced vital capacity (FEV1/FVC) was significantly lower in the overweight/obese group than in the normal BMI group (P = 0.032). There was no difference in dysanapsis and BHR between the 2 groups. There were significantly more children with moderate-to-severe asthma in the overweight/obese group compared to the normal BMI group (P = 0.018). In multivariate logistic regression analysis, overweight/obesity has been identified as an independent risk factor of affecting asthma severity (odds ratio, 2.44; P = 0.018), in addition to the already known risk factor, FEV1. Conclusion Our study showed that overweight/obese prepubertal asthmatic children had lower FEV1/FVC than those with normal BMI. It also suggests that overweight/obesity may be an independent risk factor for severe asthma before puberty.

Background/Aims: Cigarette smoking is an important modifiable risk factor in kidney disease progression. However, the underlying mechanisms for this are lacking. This study aimed to assess whether nicotine (NIC), a major toxic component of cigarette smoking, would exacerbates tacrolimus (TAC)-induced renal injury. Methods: Sprague-Dawley rats were treated daily with NIC, TAC, or both drugs for 4 weeks. The influence of NIC on TAC-caused renal injury was examined via renal function, histopathology, oxidative stress, mitochondria, endoplasmic reticulum (ER) stress, and programmed cell death (apoptosis and autophagy). Results: Both NIC and TAC significantly impaired renal function and histopathology, while combined NIC and TAC treatment aggravated these parameters beyond the effects of either alone. Increased oxidative stress, ER stress, mitochondrial dysfunction, proinf lammatory and profibrotic cytokine expressions, and programmed cell death from either NIC or TAC were also aggravated by the two combined. Conclusions Our observations suggest that NIC exacerbates chronic TAC nephrotoxicity, implying that smoking cessation may be beneficial for transplant smokers taking TAC.

Croup is a respiratory illness usually caused by acute viral infection of the larynx, trachea, and bronchi, and characterized by the abrupt onset of a barking cough, inspiratory stridor, hoarseness, and respiratory distress due to upper airway obstruction. Croup commonly affects children younger than 6 years of age, with peak incidence between 7 and 36 months. Although the disease is usually self-limited, it may occasionally become life threatening, and can, on rare occasion, lead to respiratory failure.Current Concepts: Treatment of viral croup depends on the severity of symptoms as denoted by Westley croup score (i.e., mild, moderate, or severe). A single dose of oral or intramuscular dexamethasone (0.15-0.6 mg/kg) is the mainstay of treatment for viral croup, irrespective of severity. A single dose of nebulized budesonide (2 mg) is equally effective as systemically administered dexamethasone, and is considered when a patient is unable to take a medicine orally. Nebulized L-epinephrine (1:1,000, 3-5 mL) causes vasoconstriction in the mucosa, rapidly reducing airway edema. Addition of nebulized L-epinephrine is indicated in the patients with croup of at least moderate severity, displaying chest retraction and signs of labored breathing.Discussion and Conclusion: The most effective pharmacological treatments for patients with viral croup are oral or intramuscular dexamethasone, and nebulized L-epinephrine. Especially, corticosteroids can significantly decrease the intensity of croup symptoms and reduce hospital admissions, return visits to emergency department and length of stay in the hospital.

1,2-Diacetylbenzene (DAB) is a metabolite of 1,2-diethylbenzene, which is commonly used in the manufacture of plastics and gasoline. We examined the neurotoxic effects of DAB in young and old rats, particularly its effects on hippocampus. Previously, we reported DAB impairs hippocampal neurogenesis but that the underlying mechanism remained unclear. In this study, we evaluate the toxicities exhibited by DAB in the hippocampi of 6-month-old (young) and 20-month-old (old) male SD rats by treating animals intraperitoneally with DAB at 3 mg/kg/day for 1 week. Hippocampal areas were dissected from brains and RNA was extracted and subjected to RNA-seq analysis. RNA results showed animals exhibited age-dependent sensitivity to the neurotoxic effects of DAB. We observed that inflammatory pathways were up-regulated in old rats but that metabolism- and detoxification-related pathways were up-regulated in young rats. This result in old rats, especially upregulation of the TREM1 signaling pathway (an inflammatory response involved in Alzheimer’s disease (AD)) was confirmed by RT-PCR. Our study results provide a better understanding of age-dependent responses to DAB and new insight into the association between DAB and AD.

Croup is a respiratory illness usually caused by acute viral infection of the larynx, trachea, and bronchi, and characterized by the abrupt onset of a barking cough, inspiratory stridor, hoarseness, and respiratory distress due to upper airway obstruction. Croup commonly affects children younger than 6 years of age, with peak incidence between 7 and 36 months. Although the disease is usually self-limited, it may occasionally become life threatening, and can, on rare occasion, lead to respiratory failure.Current Concepts: Treatment of viral croup depends on the severity of symptoms as denoted by Westley croup score (i.e., mild, moderate, or severe). A single dose of oral or intramuscular dexamethasone (0.15-0.6 mg/kg) is the mainstay of treatment for viral croup, irrespective of severity. A single dose of nebulized budesonide (2 mg) is equally effective as systemically administered dexamethasone, and is considered when a patient is unable to take a medicine orally. Nebulized L-epinephrine (1:1,000, 3-5 mL) causes vasoconstriction in the mucosa, rapidly reducing airway edema. Addition of nebulized L-epinephrine is indicated in the patients with croup of at least moderate severity, displaying chest retraction and signs of labored breathing.Discussion and Conclusion: The most effective pharmacological treatments for patients with viral croup are oral or intramuscular dexamethasone, and nebulized L-epinephrine. Especially, corticosteroids can significantly decrease the intensity of croup symptoms and reduce hospital admissions, return visits to emergency department and length of stay in the hospital.