High-flow nasal cannula therapy for children with complex chronic disease in the general ward: A single, tertiary center experience

Purpose@#We aimed to evaluate the usefulness and safety of high-flow nasal cannula (HFNC) oxygen therapy in children with complex chronic diseases (CCD) with impending respiratory failure in the general ward. @*Methods@#Medical records of subjects with HFNC oxygen use in the general ward at a Korean tertiary children’s hospital were reviewed. Children with CCD and impending respiratory failure were included. treatment success was defined as successful weaning from HFNC oxygen support and treatment failure as weaning failure that led to higher level of respiratory support such as invasive ventilation or noninvasive positive pressure ventilation. @*Results@#Fifty cases were included. Thirty-five cases (70%) were weaned off HFNC oxygen successfully, 15 cases (30%) failed. At the time of HFNC oxygen administration, the treatment failure group showed higher heart rate (P = 0.043), carbon dioxide partial pressure (P = 0.002), and initial inspired oxygen fraction (P = 0.007). Within 72 hours of initial treatment, 20% of patients in the treatmentsuccess group were weaned off the HFNC oxygen and half in the treatment-failure group required invasive ventilation. One case experienced complication. @*Conclusion@#HFNC oxygen is safe and effective for respiratory support in the general ward to avoid invasive mechanical ventilation in children with CCD and impending respiratory failure.

Changes in prescribing patterns and resultant disease control after lamotrigine-related adverse drug reactions: A descriptive analysis

Purpose@#This study aimed to describe the desperate situation where the clinician should make decisions to further manage patients having experienced adverse drug reaction (ADR) to lamotrigine that is indicated to not easily controlled neuropsychiatric diseases. @*Methods@#A descriptive analysis was done by thoroughly reviewing medical records of patients who were reported to have ADR to lamotrigine in a regional drug-safety center between 2010 and 2018. @*Results@#Eighty-four cases of lamotrigine-related ADRs occurred in 80 patients. Skin lesions were most commonly observed in 70 cases (83.3%) and 14 cases (16.7%) had severe ADRs. Sixty-three subjects (78.8%) discontinued lamotrigine, while 17 (21.3%) continued it.At the time of discontinuation, 30.0% were prescribed aromatic antiepileptic drugs. Among 4 subjects who were eventually prescribed lamotrigine again after a period of discontinuation, 3 (75.0%) experienced its recurrence. Among patients who had taken alternative medications, the incidence of ADRs was higher in those being prescribed aromatic antiepileptic drugs than in the others being prescribed other than aromatic antiepileptic drugs (P = 0.013). Regarding the control of underlying diseases, as many as 65 (86.7%) and 68 (90.7%) failed to reach maintaining the resolved state from 6 months and 12 months after the substitution, respectively. @*Conclusion@#Patients can be easily trapped between the recurrence of ADRs and the treatment failure to a certain drug like lamotrigine, in which we can hardly find a reasonable alternative to manage them.

Expert opinion: The clinical usefulness of skin tests prior to the administration of beta-lactam antibiotics

An allergy skin test is used to diagnose certain allergies by identifying sensitized allergens. In other words, it is a test for patients who are already sensitized to certain allergens. Because of the prevailing perception that beta-lactam allergy can be dangerous and potentially lethal, the intradermal test has long been routinely performed before use to screen beta-lactam allergy in Korea. The prevalence of penicillin allergy is estimated to be 1% to 2%. However, only 14% of the subjects with perceived penicillin allergy is considered to have true penicillin allergy. Moreover, it is difficult to justify performing a skin test on subjects who are very unlikely to be sensitized to beta-lactam, such as those who never used beta-lactam or never experienced allergy after previous use of beta-lactam.Therefore, allergists recommend beta-lactam skin testing in those who have allergy after the use of beta-lactam. Nevertheless, many hospitals in Korea are conducting routine skin tests on patients regardless of a history of beta-lactam allergy, which are not clinically validated but consume considerable human and material resources. False-positive results can consequently result in inappropriate labeling of beta-lactam allergy, leading to the unnecessary restriction of medication prescriptions and the increase in medical expenses. Herein, the drug allergy working group affiliated with the Korean Academy of Asthma, Allergy, and Clinical Immunology announces an expert opinion on the preuse beta-lactam skin test for subjects without a history of beta-lactam allergy based on the objective evidence from the literature and clinical relevance.

Management of hereditary angioedema in pediatric, pregnant, and breast-feeding patients: An expert opinion

Hereditary angioedema (HAE) is a rare inherited condition marked by recurrent skin and submucosal edema. HAE is caused by a C1 inhibitor deficiency or decreased C1 inhibitor function. The initial attack may occur during childhood or pregnancy, with symptoms ranging from classic angioedema to nonspecific stomach cramps. In this review, we discuss strategies for children and pregnant women to manage HAE attacks effectively and safely in light of the recent increase in HAE diagnosis. To begin, aggressive work-up is necessary to confirm HAE–1/2 and to determine the most effective countermeasures. Secondly, in the event of an acute attack, plasma-derived C1-inhibitor is the first line of defense for children and pregnant women. Icatibant is also appropriate for use, except in pregnant women. Fresh frozen plasma (FFP) may be suggested as an alternative. Thirdly, proactive measures to prevent HAE attacks should be considered whenever a procedure is performed that may result in an exacerbation. Finally, FFP, attenuated androgen and antifibrinolytic agents are recommended for long-term prophylaxis in South Korea where the C1-inhibitor is scarce. However, when making a decision, it is necessary to consider both the efficacy and the risk of adverse effects. For proper management, written action plans and first-aid kits are required. The action plans should be customized to the patients‘ unique circumstances.

An infant with subglottic cysts presenting as abruptly-progressed stridor and respiratory distress 2 months after extubation

Subglottic cysts are rare but can cause significant airway obstruction that potentially threatens infants’ lives. It is critically important to suspect subglottic cysts in infants with upper-airway obstructive symptoms because it can be treated effectively with only marsupialization without tracheostomy or complicated surgery. Here, we report an infant case of subglottic cyst, who showed prominent stridor and respiratory distress that abruptly progressed 2 months after extubation. The patient was born prematurely and had a history of endotracheal intubation in for a total of 16 days. He was stable with minimal stridor without respiratory distress until he was successfully discharged from the neonatal intensive care unit. However, he showed abrupt progress in stridor and respiratory difficulty about 2 weeks after discharge. Laryngoscopic exam revealed multiple subglottic cysts obstructing the trachea, and all of them were successfully removed by marsupialization. No recurrence of subglottic cysts was observed for 12 months thereafter. Subglottic cysts should be primarily suspected in infants with stridor, especially with a history of prematurity and intubation. Increased awareness of this fatal but curable condition is needed for timely and proper management.

Diagnosis and treatment of hereditary angioedema: An expert opinion

Hereditary angioedema (HAE) is a rare disease, but it severely interrupts daily life activities and can sometimes be life-threatening. Therefore, early diagnosis and prompt treatment of HAE attacks are critical. Physicians should be aware of how to diagnose and manage HAE to prepare not to miss a diagnosis when treating HAE patients. Physicians must also carry out tests to confirm the diagnosis of HAEs caused by C1 inhibitor deficiency (type 1) or C1 inhibitor dysfunction (type 2) in patients with recurrent angioedema. In addition, recent studies revealed another type of HAE which is not related to C1 inhibitor (normal C1 inhibitor HAE). Once HAE is confirmed, patients and their caregivers should be given with short-term and long-term treatment plans to relieve or prevent HAE attacks. HAE requires life-long measures, including psychological support for patients and self-management education.

Immunologic analysis of patients with postinfectious bronchiolitis obliterans

Purpose@#This study aimed to analyze the immunologic profile of children with postinfectious bronchiolitis obliterans (PIBO) in order to approach pathophysiology affected by host factors. @*Methods@#A total of 10 children with PIBO were prospectively enrolled. We obtained information on demographics from their caregiver and electric medical records. Peripheral blood samples were collected before cyclic systemic methylprednisolone therapy and complete blood count, immunoglobulin level and lymphocyte subset were analyzed. @*Results@#The white blood cell count and immunoglobulin level were within the normal range in children with PIBO. The CD4+/CD8+ ratio was not significantly different from those of the healthy control group. A decreased proportion of both central memory T cells (median [interquartile range]; 13.5% [8.3%–16.3%] vs. 18.5% [15.9%–24.1%], P = 0.01) and effector memory T cells (10.3% [5.0%–18.4%] vs. 20.9% [16.6%–26.3%], P = 0.03) in CD4+T cells was observed in the PIBO group compared with those in the control group. In CD8+T cells, the proportion of effector memory T cells (7.8% [4.2%–13.8%] vs. 24.3% [15.3%–27.9%], P = 0.02) and CD45RA+effector memory T cells (16.2% [11.0%–36.6%] vs. 24.2% [17.1%–39.7%], P = 0.04) was decreased in the patient group compared with the control group. @*Conclusion@#It is suggested that T lymphocyte subset abnormalities may be associated with a decrease in the ability to differentiate the T cells immediately upon reinfection and induce an effective response to infection. These results may partially explain the pathophysiological individual vulnerabilities to PIBO after lower respiratory tract infections in children.

Descriptive analysis on sleep-disordered breathing in children with Prader-Willi syndrome

Purpose@#Sleep-disordered breathing is one of the complicating characteristics in patients with Prader-Willi syndrome (PWS). No detailed description and risk factors are suggested on breathing problems during sleep in Korean children with PWS. @*Methods@#We reviewed clinical and sleep-study data in patients with PWS who underwent polysomnography before they took the growth hormone therapy. @*Results@#Of the 27 patients with PWS, 25 (92.6%) had sleep-disordered breathing, of whom 14 showed moderate to severe sleep apnea. Obstructive dominance was prevalent (64%), followed by central dominance (24%). The apnea-hypopnea index (AHI) increased with increasing weight-for-height z-score (WHZ) (r = 0.50, P = 0.009), but did not differ by age. Apnea duration of over 12 months was longer in the patient group than in the infant group (15.1 ± 4.3 seconds vs. 9.4 ± 1.7 seconds, P = 0.001) and in the obese than nonobese groups (16.8 ± 4.3 seconds vs. 10.0 ± 2.0 seconds, P = 0.003). Desaturation below 70% was more common in the obese than nonobese subjects (3/9 vs. 0/18, P = 0.029). Age was not different between the central and obstructive apnea groups, but patients with central apnea tended to be younger than patients with obstructive apnea (median [range]: 8.0 months [6.0–12.0 months] vs.16.5 months [8.5–79.5 months], P = 0.092). In addition, patients with obstructive apnea showed higher AHI (12.8 [5.9–19.2] vs. 3.9 [3.4–4.5], P = 0.045). @*Conclusion@#Sleep-disordered breathing is common in PWS children with different intensity and patterns according to age and BMI. Close monitoring of breathing problems during sleep is required in PWS patients.

Clinical features and pulmonary function in children with Swyer-James-Macleod syndrome: A single center experience

Purpose@#Swyer-James-Macleod syndrome (SJMS) is a rare disorder characterized by the hyperlucency of a unilateral lung due to ipsilaterally arrested lung growth. No sufficient information on progressive lung function changes during growth is available in SJMS. @*Methods@#We retrospectively reviewed SJMS cases using a clinical database from January 2000 to August 2018. @*Results@#A total of 40 patients were enrolled in this study. The median age of the patients was 4.8 years (interquartile range [IQR], 2.7–9.0 years), boys (n = 21, 52.5%) were more affected, and left lungs (n = 27, 67.5%) were more involved. The interval between infection and diagnosis was 1.8 years (IQR, 0.7–6.4 years). Mycoplasma pneumoniae (n = 14) and adenovirus (n = 5) were most prevalent among the 21 subjects with presumably identifiable causes. Most of the 16 patients with available pulmonary function data presented moderate obstructive lung function (z-score, median; FEV 1: -4.320 [IQR, -5.955 to -3.400] and FVC: -2.600 [IQR, -3.590 to -1.570], respectively) with the more decreased median in forced expiratory flow between 25% and 75% of FVC (FEF 25%–75%) (z-score, -4.470; IQR, -5.330 to -3.170). Linear mixed effect models indicated that younger age at first infectious insult was significantly related to decreased FEV1 z-score (P = 0.041), and that the FEV 1/FVC and FEF 25%–75% z-scores were reduced by 0.082 (P = 0.005) and 0.069 (P ≤ 0.001) per year. @*Conclusion@#In children with SJMS, the initial infectious insult occurs in the early life with M. pneumoniae being the most common pathogen. Lung function may deteriorate with an obstructive pattern during growth. The impairment can progress slowly not in the FEV1, but in the FEV1/FVC or FEF25%–75%

Natural courses and prognostic factors of pulmonary underdevelopment except for congenital diaphragmatic hernia

Purpose@#Pulmonary underdevelopment is one of the pulmonary causes of neonatal mortality, which is categorized into pulmonary agenesis, pulmonary aplasia, and pulmonary hypoplasia. Congenital diaphragmatic hernia is a well-known cause of pulmonary hypoplasia; however, further studies are needed for other etiologies. Patients with pulmonary underdevelopment show varying degrees of clinical severity. Most patients with pulmonary underdevelopment have respiratory distress at birth, while a few have only mild symptoms. Our study investigated the natural course and prognosis of pulmonary underdevelopment by analyzing multiple cases from a single tertiary medical center. @*Methods@#A retrospective review was conducted on patients diagnosed with pulmonary hypoplasia and agenesis from January 2000 to August 2019. Cases were extracted from the clinical database of Seoul National University Children’s Hospital by searching for keywords related to pulmonary underdevelopment. @*Results@#A total of 28 patients were identified. Four patients had pulmonary agenesis, and all were idiopathic. Twenty-four patients had evidence of pulmonary hypoplasia with diverse causes. The median age at diagnosis was 11.5 days (range, 1–240 days) and the mean gestational age was 35 weeks 2 days± 3 weeks 6 days. Twenty patients received ventilator care and 11 had various degrees of pulmonary hypertension. The long-term survival rate was 50%. The median age of death among pulmonary hypoplasia patients were 11 days (range, 1–730 days). All patients without ventilator care survived. The incidence of ventilator care, pneumothorax, and pulmonary hypertension were significantly higher among patients who died. @*Conclusion@#The prognosis of pulmonary underdevelopment depends on the severity of respiratory distress and pulmonary hypertension in earlier life. Patients with severe distress appear to have severe degree of pulmonary hypoplasia. Patients without ventilator support in the neonatal period survived without significant morbidities.

Gorham-Stout Syndrome with Focal Segmental Glomerulosclerosis: A Case Report

Gorham-Stout syndrome is a rare bone disorder characterized by progressive massive osteolysis and proliferation of vascular and lymphatic vessels. A 15-year-old boy was initially diagnosed with Gorham-Stout at the age of 8 years based on clinical and radiological findings. Following diagnosis, he was treated with pamidronate, interferon alfa, propranolol, oral corticosteroids, and sirolimus. He developed proteinuria at the age of 15 and progressed into the nephrotic range 2 years later. A renal biopsy revealed focal segmental glomerulosclerosis, not otherwise specified variant. The sequential increase in proteinuria associated with medications suggested that the focal segmental glomerulosclerosis may be caused by pamidronate and sirolimus, but cannot completely rule out the possibility of kidney involvement of GSS itself.

Imbalance of Gut Streptococcus, Clostridium, and Akkermansia Determines the Natural Course of Atopic Dermatitis in Infant

PURPOSE: The roles of gut microbiota on the natural course of atopic dermatitis (AD) are not yet fully understood. We investigated whether the composition and function of gut microbiota and short-chain fatty acids (SCFAs) at 6 months of age could affect the natural course of AD up to 24 months in early childhood.METHODS: Fecal samples from 132 infants were analyzed using pyrosequencing, including 84 healthy controls, 22 transient AD and 26 persistent AD subjects from the Cohort for Childhood Origin of Asthma and Allergic Diseases (COCOA) birth cohort. The functional profile of the gut microbiome was analyzed by whole-metagenome sequencing. SCFAs were measured using gas chromatography-mass spectrometry.RESULTS: Low levels of Streptococcus and high amounts of Akkermansia were evident in transient AD cases, and low Clostridium, Akkermansia and high Streptococcus were found in children with persistent AD. The relative abundance of Streptococcus positively correlated with scoring of AD (SCORAD) score, whereas that of Clostridium negatively correlated with SCORAD score. The persistent AD group showed decreased gut microbial functional genes related to oxidative phosphorylation compared with healthy controls. Butyrate and valerate levels were lower in transient AD infants compared with healthy and persistent AD infants.CONCLUSIONS: Compositions, functions and metabolites of the early gut microbiome are related to natural courses of AD in infants.

Risk Factors and Comorbidities Associated With the Allergic Rhinitis Phenotype in Children According to the ARIA Classification

PURPOSE: Data are lacking on the association between the allergic rhinitis (AR) phenotype and sensitization to specific allergens or bronchial hyperresponsiveness (BHR) in children. We here investigated risk factors and comorbidities, including sensitization to specific allergens and BHR, for the AR phenotype by AR and its Impact on Asthma (ARIA) classification in a general population-based birth cohort study. METHODS: We enrolled 606 children aged 7 years from the Panel Study of Korean Children. The AR phenotype was assigned in accordance with the ARIA classification in children. Skin prick tests and Provocholine provocation test were performed. Risk factors and comorbidities for AR phenotypes were then analyzed. RESULTS: The prevalence of mild and moderate to severe AR in our study cohort was 37.2% and 8.8%, respectively. Recent use of analgesics or antipyretics and current cat ownership were associated with the risk of mild persistent AR. Sensitizations to Dermatophagoides Pteronyssinus (Der p), Japanese hop and cat were associated with moderate to severe persistent AR. Children with moderate to severe AR had a higher risk of current asthma and BHR compared to mild AR cases (adjusted odds ratio [aOR], 5.26; 95% confidence interval [CI], 1.77–15.62). Moderate to severe AR with allergic sensitization was associated with the highest risk of BHR (aOR, 11.77; 95% CI, 3.40–40.74). CONCLUSIONS: Moderate to severe-persistent AR is more closely related to respiratory comorbidities and sensitizations than mild AR. Stratifying the AR phenotype by ARIA classification may assist in disease management.

Associated Factors for Asthma Severity in Korean Children: A Korean Childhood Asthma Study

PURPOSE: Childhood asthma has a considerable social impact and economic burden, especially in severe asthma. This study aimed to identify the proportion of childhood asthma severity and to evaluate associated factors for greater asthma severity. METHODS: This study was performed on 667 children aged 5–15 years with asthma from the nationwide 19 hospitals in the Korean childhood Asthma Study (KAS). Asthma was classified as mild intermittent, mild persistent, and moderate/severe persistent groups according to the National Asthma Education and Prevention Program recommendations. Multinomial logistic regression models were used to identify the associated factors for greater asthma severity. RESULTS: Mild persistent asthma was most prevalent (39.0%), followed by mild intermittent (37.6%), moderate persistent (22.8%), and severe persistent asthma (0.6%). Onset later than 6 years of age (adjusted odds ratio [aOR], 1.69 for mild persistent asthma; aOR, 1.92 for moderate/severe persistent asthma) tended to increase asthma severity. Exposure to environmental tobacco smoke (aOR, 1.53 for mild persistent asthma; aOR, 1.85 for moderate/severe persistent asthma), and current dog ownership with sensitization to dog dander (aOR, 5.86 for mild persistent asthma; aOR, 6.90 for moderate/severe persistent asthma) showed increasing trends with greater asthma severity. Lower maternal education levels (aOR, 2.32) and no usage of an air purifier in exposure to high levels of outdoor air pollution (aOR, 1.76) were associated with moderate/severe persistent asthma. CONCLUSIONS: Modification of identified environmental factors associated with greater asthma severity might help better control childhood asthma, thereby reducing the disease burden due to childhood asthma.

The Korean Version of the Test for Respiratory and Asthma Control in Kids (TRACK): Reliability and Validity

BACKGROUND: Test for Respiratory and Asthma Control in Kids (TRACK) questionnaires were developed and validated in various languages to monitor respiratory control in preschool-aged children. We aimed to assess the reliability and validity of the Korean version of the TRACK questionnaire. METHODS: We administered the linguistically validated TRACK questionnaires to caregivers of asthmatic preschool children on two separate visits 4–6 weeks apart. Each physician graded the level of the guideline-based asthma control, assessed the timing of symptoms, and adjusted the therapeutic level at each visit. RESULTS: A total of 137 children were enrolled in the study. Cronbach's alpha was 0.65 for a questionnaire as a whole. The test-retest reliability was 0.72. The median TRACK scores were significantly different between asthma control status categories, with the lowest scores in children classified as poorly controlled and the highest in the well-controlled group (P < 0.001). They were different among groups classified according to the physician adjusted therapeutic levels, with the lowest values in children prescribed step-up therapy (P < 0.001), and according to the recency of respiratory symptoms (P < 0.001). Finally, the changes in TRACK scores between visits were highest in subjects showing improved control, followed by unchanged, and worsened control. When we applied the traditional cut-off of 80 for a well-controlled condition, a sensitivity of 75.6% and a specificity of 70.9% were calculated. CONCLUSION: The Korean translated version of the TRACK questionnaire is valid and reliable to assess respiratory and asthma control in Korean preschool children with asthma symptoms.

Efficacy and Safety of Fentanyl in Combination with Midazolam in Children on Mechanical Ventilation

BACKGROUND: To evaluate the efficacy and safety of fentanyl for sedation therapy in mechanically ventilated children. METHODS: This was a double-blind, randomized controlled trial of mechanically ventilated patients between 2 months and 18 years of age. Patients were randomly divided into two groups; the control group with midazolam alone, and the combination group with both fentanyl and midazolam. The sedation level was evaluated using the Comfort Behavior Scale (CBS), and the infusion rates were adjusted according to the difference between the measured and the target CBS score. RESULTS: Forty-four patients were recruited and randomly allocated, with 22 patients in both groups. The time ratio of cumulative hours with a difference in CBS score (measured CBS–target CBS) of ≥ 4 points (i.e., under-sedation) was lower in the combination group (median, 0.06; interquartile range [IQR], 0–0.2) than in the control group (median, 0.15; IQR, 0.04–0.29) (P < 0.001). The time ratio of cumulative hours with a difference in CBS score of ≥ 8 points (serious under-sedation) was also lower in the combination group (P < 0.001). The cumulative amount of midazolam used in the control group (0.11 mg/kg/hr; 0.07–0.14 mg/kg/hr) was greater than in the combination group (0.07 mg/kg/hr; 0.06–0.11 mg/kg/hr) (P < 0.001). Two cases of hypotension in each group were detected but coma and ileus, the major known adverse reactions to fentanyl, did not occur. CONCLUSION: Fentanyl combined with midazolam is safe and more effective than midazolam alone for sedation therapy in mechanically ventilated children. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02172014

Clinical characteristics of pediatric pneumothorax during a noninvasive positive pressure ventilation

PURPOSE: Noninvasive positive pressure ventilation (NIPPV) is one of the ventilation-supporting methods by providing adequate exogenous pressure without intubation or tracheostomy. We aimed to assess the frequency and clinical factors for pneumothorax occurring during NIPPV application in a tertiary children's hospital. METHODS: We selected cases of pneumothorax related to NIPPV by keyword searching in our institution's clinical data warehouse, and their medical records were retrospectively reviewed. RESULTS: During a period of 17 years, 15 cases undergoing NIPPV developed pneumothorax, which was an incidence of 0.64% (15 of 2,343). There were 9 neonates and 6 adolescents. In 9 neonates, pneumothorax was caused by the continuous positive airway pressure (CPAP) ventilator, and occurred on 2 days after birth (median, range 1–3 days). In neonates, pneumothorax developed within 36 hours after CPAP application. One neonate underwent tracheal intubation and 3 neonates underwent chest tube insertion. In the postteenager group, pneumothorax developed 23 months (median, range 5 days to 47 months) after NIPPV application with a mask. All of the 6 patients had underlying neuromuscular disorders and one had superimposed interstitial lung disease. One of the 7 cases underwent surgical treatment and 4 cases were intubated. One case died from the deterioration of underlying interstitial lung disease. CONCLUSION: Although it rarely happens, the NIPPV can result in pneumothorax. In most cases, it can be resolved by supportive cares with oxygen or chest tube with or without tracheostomy. The prognosis is related to the type of underlying disease and its progression.

Indoor pet ownership in infancy is a risk factor for the development of sensitization to pets and asthma in childhood

PURPOSE: It is controversial whether indoor pet exposure is either a risk or protective factor developing sensitization to pet allergens or asthma. Therefore, we investigated whether indoor pet ownership entails a risk for the development of asthma and sensitization in childhood. METHODS: The Panel Study of Korean Children (PSKC) is a general-population-based birth cohort study that recruited 2,078 mother-baby dyads in Korea between April and July of 2008. Among 1,577 children who were followed up in 2015, 559 underwent skin prick tests, spirometry and bronchial provocation tests using Provocholine. Having a cat or a dog and the prevalence of asthma were evaluated by using self-reported questionnaires and physicians’ medical records. RESULTS: During infancy, the rate of dog ownership was 4.5% (71 of 1,574) and that of cat ownership was 0.5% (8 of 1,574). Of the subjects, 7.9% (n=109) currently had at least 1 dog and 2.5% (n=34) had at least 1 cat. Pet ownership during infancy was associated with sensitization to cats or dogs (adjusted odds ratio [aOR], 4.24; 95% confidence interval [CI], 1.29–13.98), wheezing within 12 months (aOR, 5.56; 95% CI, 1.65–18.75) and current asthma (wheezing episode in the last 12 months+diagnosed asthma by physicians) (aOR, 6.36; 95% CI, 1.54–26.28). In contrast, pet ownership during the last 12 months was not associated with sensitization to cats or dogs or current asthma. CONCLUSION: Indoor pet exposure during infancy can be critical for developing sensitization to cats or dogs and asthma in childhood. Avoidance of pet exposure in early life may reduce sensitization to cats or dogs and development of asthma.

The risk of preschool asthma at 2–4 years is not associated with leukocyte telomere length at birth or at 1 year of age

BACKGROUND: Exposure to prenatal stress is associated with offspring allergic-disease development, and oxidative stress may mediate this relationship. OBJECTIVE: We aimed to evaluate whether leukocyte telomere length (LTL) shortening, a marker for exposure to oxidative stress, in early life is associated with increased risk of asthma development during the preschool period. METHODS: We assessed the follow-up clinical data of a subgroup from a birth cohort whose LTLs had been measured from cord-blood and 1-year peripheral-blood samples. We examined whether the LTLs would be associated with asthma development at the age of 2–4 years. RESULTS: The data of 84 subjects were analyzed. LTLs were measured from the cord-blood and 1-year peripheral blood of 75 and 79 subjects, respectively. Among them, 14 subjects (16.7%) developed bronchial asthma between 2–4 years old. Prenatally stressed subjects had marginally increased odds of developing asthma (p = 0.097). There was no significant difference in the odds of preschool-asthma development between the groups with shorter and longer cord-blood LTLs (odds ratio [OR], 0.651; 95% confidence interval [CI], 0.184–2.306) or in the odds between the groups with shorter and longer 1-year peripheral-blood LTLs (OR, 0.448; 95% CI, 0.135–1.483). Finally, subjects with both higher prenatal stress and shorter LTLs did not have significantly higher odds of preschool-asthma development (for cord-blood: OR, 1.242; 95% CI, 0.353–4.368; for 1-year peripheral-blood: OR, 1.451; 95% CI, 0.428–4.919). CONCLUSION: There was no significant association between early life LTLs and higher risk of bronchial-asthma development during the preschool years.

Clinical characteristics of nontraumatic chylothorax in pediatric patients

PURPOSE: To evaluate clinical characteristics of pediatric nontraumaitc chylothorax and to suggest appropriate therapeutic managements. METHODS: We retrospectively reviewed medical records of 22 patients with nontraumatic chylothorax from January 2005 to December 2018 in the Children's Hospital of Seoul National University. We analyze their etiology, treatment, complications and outcome. RESULTS: Of the 22 patients, 16 were diagnosed before 1 year old and 6 after 1 year old. The causes of chylothorax under 1-year-old children were related to congenital factors (n=9), unknown causes (n=5), and high central venous pressure (n=2). The causes of chylothorax over 1-year-old children were related to congenital factors (n=3), unknown causes (n=1), high venous pressure (n=1), and lymphoma (n=1). All patients had dietary modification. Eight of them were cured by dietary modification, but there was no improvement in over 1-year-old children. Medication was added to patients refractory to dietary modification. Four patients with medication were improved and 5 were improved by surgical management. Nutritional, immunological and other complications occurred in many patients. Five death cases were reported. Four patients were under 1 year old and 1 was over 1 year old. The causes of nontraumatic chylothorax in dead patients were high central venous pressure (n=3), congenital (n=1), and unknown (n=1). CONCLUSION: Nontraumatic chylothorax more frequently occurs in under 1-year-old children. The most common cause is congenital factors. Stepwise management is effective in many patients, but specific treatment is needed in some cases. The prognosis is related to the onset of age and underlying diseases.