Associations between pollen and allergic rhinitis in children and adolescents

Allergic rhinitis (AR) is a type of rhinitis accompanied by sensitization to allergens. One of the most clinically important allergens is pollen. Recently, due to climate change and CO 2 air pollution, the flowering period starts earlier and persists longer. In addition, antigenicity due to environmental pollution is also being strengthened. As a result, the sensitization rate to pollen antigens is on the rise. It is known that the prevalence of AR especially caused by pollen is rapidly escalating. Although the causal relationship between pollen exposure and the severity of rhinitis is not precisely established, an association of rhinitis symptoms with the time of pollen scattering exists. In addition, the mixed effect of environmental pollution and pollen may play a role in the development of rhinitis symptoms. Therefore, in order to avoid pollen, it is necessary to constantly improve pollen forecast and minimize the contact with pollen indoors and outdoors. Treatment of AR should be performed according to guidelines. Also, continuous efforts to solve the environmental problems affecting the ecology of pollen are needed.

DRESS (drug reaction with eosinophilia and systemic symptoms) syndrome induced by lamotrigine in a child

Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is a rare and severe adverse drug reaction characterized by the cutaneous eruption, fever, eosinophilia, and involvement of internal organs. It is commonly caused by aromatic anticonvulsant drugs and antibiotics in children. In this study, we presented a case of a 9-year-old boy with bipolar disorder, who developed DRESS syndrome after lamotrigine intake for 10 days. Thereafter, lamotrigine was discontinued, and systemic corticosteroid treatment was pursued for 18 days. After 3 months, a patch test for lamotrigine was performed as a confirmatory test to check drug reaction. Reports of DRESS syndrome in adults have increased over the past decade due to the increasing use of lamotrigine as a new aromatic anticonvulsant. Although there are only a few lamotrigine-related DRESS syndrome reports in children, caution is needed with its potential widespread use in the future.

Effects of outdoor air pollution on children with allergic rhinitis

The global worsening of air pollution has decreased the quality of life. Air pollutants can induce oxidative stress, epigenetic changes, and alterations to microRNA expression in the airway and skin, leading to immune dysregulation. Previous epidemiological studies suggest a strong association between outdoor environmental pollution and childhood allergic disease, especially allergic rhinitis (AR). Moreover, traffic-related air pollution has increased the severity and incidence of AR, and heavy traffic has been associated with an increased prevalence of AR. Thus, this review aimed to define outdoor environmental pollution and clarify the mechanisms by which air pollutants aggravate AR. In addition, we performed a systematic review and meta-analysis to summarize the findings of several domestic and international epidemiological and clinical studies about the effects of air pollution on AR in children.

Risk factors and protective factors in pediatric patients with allergic rhinitis

Among allergic diseases of the Korean pediatric population, allergic rhinitis shows the most rapidly increasing prevalence. Its economic burden is substantial in many Asian countries including South Korea. This investigation of its risk factors aims to reduce the socioeconomic burden by blocking exposure of susceptible individuals to identified causes. However, the risk factors of allergic rhinitis varied considerably depending on the seasons, geographical locations, and populations involved. This review article primarily deals with studies on the risk factors for allergic rhinitis in Korean children that were published during the last 10 years and additionally investigates associated large scale international studies. Our investigation identified several single-nucleotide polymorphisms, inhalant allergens, pollution, tobacco smoke, chemicals, and family affluence as risk factors for allergic rhinitis. In contrast, breastfeeding, older sibling, and microbial diversity were protective factors against allergic rhinitis. This suggests that various genetic and environmental factors might affect the manifestation and presentation of allergic rhinitis complexly. These findings are beneficial as they can provide insights into modifiable risk factors that may hinder the development of allergic rhinitis.

Main epidemiological characteristics and natural history of pediatric allergic rhinitis

Allergic rhinitis (AR) is one of the most common allergic diseases characterized by stuffy nose, rhinorrhea, sneezing, and itching. Researchers have indicated an increase in the prevalence of AR and younger-age onset during the last few decades. The increasing burden of AR has caused many researchers to investigate time trends of the prevalence of AR and to identify its risk factors. The most commonly used epidemiological studies are cross-sectional ones such as the International Study of Asthma and Allergies in Childhood study and big data from National Health Insurance Service or National Health and Nutrition Examination Survey. However, these studies have many limitations including recall bias, selection bias, and deficit of objective evaluation. Furthermore, crosssectional studies cannot reflect new risk factors associated with the development of AR. New epidemiological studies will be needed to cover genetic factors, environmental changes, microbiomes, and lifestyles that are known to be risk factors for AR. Further studies will be needed to determine the prevalence, natural history, and risk factors of AR in order to advance our understanding of the pathophysiology, prevention, and management of comorbidities of AR.

Anaphylaxis to honey

Honey is a food ingested worldwide. Allergic reaction to honey is rare and only a few cases have been reported in the literature. A 20-month-old boy developed angioedema 30 minutes after eating rice cake containing honey. After 2 weeks, we performed food challenge tests with honey which resulted in anaphylaxis. This is the first case report on anaphylaxis to honey in Korea.

The association between nasal eosinophilia and aeroallergen sensitization in children and adolescents with rhinitis

PURPOSE: To identify the correlation between nasal eosinophilia and aeroallergen sensitization in children and adolescents. METHODS: This is a retrospective study of patients below 18 years of age who had a history of rhinitis that lasted more than 2 weeks or had been repeated more than once a year, received nasal eosinophil examinations, and had serum specific IgE to aeroallergens measured at an Allergy Clinic in a single tertiary teaching hospital in Seoul, Korea. The percentage of nasal eosinophils was calculated by the number of eosinophils per total leukocytes in a high-power field of 1,000×. Data was analyzed to determine the association between nasal eosinophilia and 18 aeroallergens. RESULTS: Of the 245 patients included, 156 (63.7%) were male and the mean age (±standard deviation) was 7.9 years (±3.8). In total, 175 patients (71.4%) were sensitized to at least 1 of the 18 aeroallergens tested, and sensitization to house dust mite was most common. In addition, 118 (48.2%) and 69 patients (28.2%) had nasal eosinophilia of at least 1% and 5%, respectively. There were no significant correlations between serum total IgE or age and the percentage of nasal eosinophils. However, the percentage of nasal eosinophils in the group sensitized to any aeroallergens was significantly increased compared to the nonsensitized group (P=0.002). The percentage of nasal eosinophils was significantly higher in patients who were sensitized to Birch-Alder Mix, oak white, Bermuda grass, orchard grass, timothy grass, sweet vernal grass, rye, mugwort, short ragweed, Alternaria alternata, cats, dogs or Dermatophagoides farinae compared to those nonsensitized. CONCLUSION: Nasal eosinophilia was significantly associated with sensitization to aeroallergens.

Chest radiographs and computed tomography scans in children with airway foreign body

PURPOSE: This study aimed to evaluate the diagnostic value of radiologic findings in children with suspected foreign body aspiration. METHODS: A retrospective medical chart review was done on 32 children with suspected foreign bodies in terms of age, sex, symptoms, signs, bronchographic findings, and type and location of foreign bodies. The diagnostic value of radiography was analyzed: 29 with chest anteroposterior (AP) or posteroanterior (PA) view, 23 with chest lateral decubitus view, 27 with chest computed tomography (CT), 29 with chest AP, PA or chest lateral decubitus view, and 25 with bronchoscopy. RESULTS: As a measure for detecting foreign body aspiration, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of radiologic findings were: chest AP or PA view, 50%, 100%, 100%, 29.4%, and 58.6%, respectively; chest lateral decubitus view, 57.9%, 50.0%, 84.6%, 20.0%, and 56.5%, respectively; chest AP, PA or chest lateral decubitus view, 69.6%, 66.7%, 88.8%, 36.4%, and 69.0%, respectively; and chest CT, 100.0%, 85.7%, 95.2%, 100.0%, and 96.2%, respectively. CONCLUSION: There is clinical benefit to take chest radiographs to diagnose foreign body aspiration. However, based on the results of this study, it may be not necessary to take chest lateral decubitus to diagnose foreign body aspiration. If chest radiographs show unilateral hyperinflation, foreign body aspiration can be diagnosed. In cases of normal chest radiography and history of a witnessed choking episode combined with positive signs, the diagnosis of airway foreign body aspiration should be made by using chest CT.

Diagnostic value of serum IgM enzyme-linked immunosorbent assays in polymerase chain reaction-positive Mycoplasma pneumonia in children

PURPOSE: Mycoplasma pneumoniae (MP) is a common cause of community-acquired pneumonia (CAP) in children. MP serum IgM and polymerase chain reaction (PCR) are the methods that enable early diagnosis in patients with MP pneumonia. The objective of this study was to investigate the clinical value of serum MP-specific IgM antibodies in PCR-positive MP pneumonia for the early diagnosis of MP pneumonia in children with CAP. METHODS: Out of 129 patients with lower respiratory tract infection aged over 3 years, 90 CAP children were enrolled in the study. Throat swab MP real-time PCR and serum enzyme-linked immunosorbent assays (ELISA) IgM antibodies were performed. A positive rate of MP PCR and serum IgM, the level of IgM index, clinical features, and laboratory findings were analyzed. RESULTS: PCR was positive in 57 cases. Longer fever duration before admission (P < 0.001), higher rates of lobar or segmental pneumonia (P=0.048), unilateral infiltration (P=0.038), and extrapulmonary symptoms (P=0.049) were associated with MP PCR-positive pneumonia. Serum IgM index was significantly higher in MP PCR-positive pneumonia them in MP PCR-negative pneumonia (3.9±3.0 vs. 0.8±1.3, P < 0.001). Using MP PCR as a gold standard, the sensitivity, specificity, positive predictive value and negative predictive value of serum IgM were 85.5%, 82.1%, 91.4%, and 71.9%, respectively. The area under the curves for serum IgM index was 0.892, and the ROC analysis indicated that an optimal cutoff value of 1.05 for serum IgM provided the highest sensitivity and specificity interestingly (83.9% vs. 85.7%, P < 0.001). CONCLUSION: Serum IgM ELISA has useful diagnostic value in PCR-positive MP pneumonia. Applying an IgM index cutoff of 1.05 improves diagnostic accuracy.

Effect of Proparacaine in a Mouse Model of Allergic Rhinitis

OBJECTIVES: Lidocaine, a local anaesthetic is a treatment option in uncontrolled asthma due to its immunomodulatory effects. In the present study, proparacaine (PPC), a derivative of lidocaine was examined for its therapeutic application in a mouse model of allergic rhinitis. METHODS: The mice were grouped into 4 groups: control group, allergic rhinitis (AR) group, ciclesonide (CIC) group, and PPC group. Nasal symptom scores, eosinophil counts, goblet cell counts, and mast cells counts in the nasal mucosa were measured. Serum ovalbumin (OVA)-specific immunoglobulin (Ig) E, OVA-specific IgG1, OVA-specific IgG2a, interleukin (IL)-4, IL-5, and cortisol levels were measured. RESULTS: Intranasal administration of PPC significantly decreased nasal symptoms, number of eosinophils, goblet cells, and mast cells in the lamina propria of the nasal mucosa. Serum OVA-specific IgE, OVA-specific IgG1, OVA-specific IgG2a was significantly higher in the AR compared with the control group. Serum level of IL-4 was significantly lower in the CIC group and PPC group in comparison with AR group. Serum IL-5 showed no significant difference among all groups. No significant difference in serum cortisol levels was observed among the 4 groups. CONCLUSION: PPC appears to have a therapeutic potential in treatment of allergic rhinitis in a mouse model by reducing eosinophil, goblet cell, and mast cell infiltration in the nasal mucosa.

Usefulness of flexible bronchoscopy in children with suspected pulmonary tuberculosis who have difficulty in sputum expectoration

PURPOSE: To assess the usefulness of flexible bronchoscopy in patients with suspected pulmonary tuberculosis (PTB) who have difficulty in sputum expectoration. METHODS: The subjects of this study were patients who were suspected of PTB and visited the Division of Pediatric Pulmonology at a tertiary hospital from April 2006 to March 2016. PTB suspects were determined by clinical symptoms, radiologic findings, and immunologic studies. We aimed to examine the value and safety of bronchoscopy in diagnosis and differential diagnosis of PTB in PTB-suspected patients. The diagnostic criteria for PTB were defined when Mycobacterium tuberculosis was cultured in the sputum specimen or in the bronchial washing fluid. RESULTS: A total of 19 PTB suspects were included. One patient was diagnosed with PTB by using the sputum study. However, the remaining 18 patients could not expectorate sputum or showed no evidence of Mycobacterium tuberculosis infection from the sputum study. Of the 18 patients, 15 underwent bronchoscopy. After bronchoscopy, 6 patients were diagnosed with PTB and 9 patients were diagnosed with Mycoplasma, viral, or fungal pneumonia, and tumors. For antituberculous drug resistance, there were 1 case of isoniazid (INH) resistance and 1 case of concurrent resistance to INH and prothionamide. There was no multidrug-resistant tuberculosis. None of the patients had significant complications due to bronchoscopy. CONCLUSION: Flexible bronchoscopy appears to be a definitive and safe procedure for the differential diagnosis of patients suspecting PTB in children who have difficulty expectorating sputum.

Correlation between serum cytokines and clinical feature of children with mild lower respiratory infection

PURPOSE: Acute lower respiratory infection (ALRI), which is frequently encountered in pediatric patients, is the leading cause of hospitalization. We aimed to identify particular cytokines that correlated with ALRI clinical characteristics. We also aimed to identify any differences in cytokines between respiratory syncytial virus (RSV)-related ALRI and non-RSV-related ALRI. METHODS: Cytokine levels were measured in the sera sampled from 103 pediatric patients diagnosed with ALRI and admitted to Seoul St. Mary's Hospital between May 2012 and April 2013. The correlations between cytokine levels and the length of hospitalization, the number of days with fever, body temperature, pulse rate, respiration rate, oxygen saturation upon admission, and duration of oxygen supplementation were analyzed. RESULTS: In children with ALRI, the level of interleukin (IL)-6, granulocyte-colony stimulating factor (G-CSF), and IL-10 were correlated with a higher body temperature on admission. In addition, the IL-8 level was correlated with pulse rate and respiration rate, and IL-1β level was related with oxygen saturation on admission. In children with RSV-related ALRI, the IL-6 was correlated the with duration of fever, and the IL-1β, IL-2, and IL-8 levels were related to pulse rate and respiration rate. In addition, the increase in interferon-gamma-inducible protein-10 (IP-10) level was correlated with a higher body temperature on admission and a longer duration of hospitalization in children with RSV-related ALRI. CONCLUSION: In children with ALRI, the levels of IL-6, IL-8, IL-1β, G-CSF, and IP-10 were correlated with its clinical features. In children with RSV-related ALRI, the IL-1β, IL-2, IL-6, IL-8, and IP-10 level was correlated with the severity of the disease.

Clinical characteristics of interferon-gamma-inducible protein of 10 kDa in children with wheezing

PURPOSE: Recent studies have shown that interferon-gamma-inducible protein of 10 kDa (IP-10/CXCL10) levels is increased in acute bronchiolitis and asthma. The aim of this study was to examine the levels of IP-10 in children with wheezing and whether it correlates with other clinical variables. METHODS: A total of 62 subjects children were hospitalized for lower respiratory tract infection with wheezing and visited the Emergency Department due to an acute exacerbation of asthma. IP-10 levels were measured using enzyme-linked immunosorbent assay in the serum collected at admission. Serum IP-10 levels were evaluated for the relationships with age, sex, blood eosinophils counts, acute phase reactant, allergic sensitization, history of wheezing, and chest X-ray findings. RESULTS: Age showed a significant negative correlation with serum IP-10 levels (P=0.002). The serum levels of IP-10 were also significantly increased in patients with pneumonic infiltration on X-rays compared to those with normal or hyperinflation (P<0.009). There was no significant difference in the serum IP-10 level according to the other factors, including allergic sensitization. CONCLUSION: Serum IP-10 is significantly associated with inflammation of the lung and age, but not with allergic inflammation.

Flexible bronchoscopy in 76 children: Indications, yield, and complications

PURPOSE: This study was performed to investigate the indications, yield, and complications of flexible bronchoscopy for respiratory disease in children compared to earlier domestic studies and to examine if any differences existed in comparison to international studies. METHODS: The medical records of 100 cases of flexible bronchoscopy that were performed in 76 patients at the Department of Pediatrics of The Catholic University of Korea, Seoul St. Mary's Hospital from June 16, 2010 to August 6, 2013 were reviewed. RESULTS: A total of 76 patients (50 males and 26 females) were included in the study. The most common indication of flexible bronchoscopy was persistent pneumonia or pneumonia in immunocompromised patients (53 cases). The object of flexible bronchoscopy was accomplished in 65 of 100 cases, and, the treatment was changed in 24 of 65 cases. The most common abnormal finding was tracheomalacia that was found in 18 cases. In 67 cases where bronchoalveolar lavage was performed, bacteria were identified in 47 cases, fungi in 9 cases, and viruses in 22 cases. Complications occurred in 8 cases. CONCLUSION: Compared to earlier domestic studies, there was no significant change in diagnostic approaches and therapeutic improvement. However, this study showed that flexible bronchoscopy appears to be safe in patients with hemato-oncologic disease. Compared to international studies, the occurrence of complications due to flexible bronchoscopy was relatively low.

Foreign body aspiration in 48 children: clinical manifestations and outcomes

PURPOSE: This study aimed to have a deeper insight into the clinical spectrum of foreign body aspiration in children and to prospect the further clinical implications of early diagnosis. METHODS: We conducted a retrospective medical chart review of 48 children with foreign bodies at The Catholic University of Korea, Seoul St. Mary's Hospital, between January 2009 and December 2013 in terms of age, sex, symptoms and signs, radiologic findings, and clinical courses. Patients were divided into 2 groups according to the time from aspiration to a definite diagnosis. The 2 groups were compared for clinical courses, radiologic findings, and the length of hospitalization. RESULTS: Approximately 85% of patients were 3 years of age or younger. About one-fifth of patients had no history of foreign body aspiration. Cough and coarse breathing sounds were the most common symptoms and signs. The most frequent radiologic finding was pulmonary air trapping (33.3%). The mostly commonly aspirated foreign body was peanut and detected in left main bronchus. Cough, sputum, and absence of aspiration history were more common in the delayed diagnosed group than in the early diagnosed group. CONCLUSION: Our results suggest that the number of accidents associated with foreign body aspiration can be reduced by keeping infants with nut formula under close observation and by conducting assertive bronchoscopic examination on children with delayed recovery from respiratory infections. After removal of foreign bodies, close monitoring and expectation of possible complications can prevent patients from a long hospital stay.

Immunoglobulin E to allergen components of house dust mite in Korean children with allergic disease

BACKGROUND: House dust mites (HDMs) are important sources of indoor allergens. Seventeen components have been identified from Dermatophagoides pteronyssinus (Der p). OBJECTIVE: Our aim was to define the prevalence of specific IgE to components of Der p in Korea and investigate the clinical features of them in children with allergic disease. METHODS: We performed a prospective evaluation of 80 HDM sensitized patients with history of allergic rhinitis (AR), atopic dermatitis (AD), asthma and urticaria (UC). Patients underwent ImmunoCAP for total IgE, Der p, Der f, Der p 1, Der p 2, and Der p 10. RESULTS: Seventy-nine patients had detectable serum IgE to Der p, 80 patients were sensitized to Der f, 66 patients were sensitized to Der p 1, 63 patients to Der p 2, and 7 patients were sensitized to Der p 10. Der p 1 specific IgE was significantly lower in the UC group compared with the AD and AR group. Total IgE was significantly higher in the Der p 10 sensitized group. Der p 10 serum IgE level was highly correlated with crab and shrimp specific IgE. There was a significant positive correlation between total IgE and specific IgE to Der p and its components and Der f. CONCLUSION: Sensitization to HDM and its components in Korea is similar to previous studies from temperate climate. The determination of Der p 1, Der p 2, and Der p 10 specific IgE helps in obtaining additional information in regards to allergic disease.

Pertussis Accompanying Recent Mycoplasma Infection in a 10-Year-Old Girl

Recently, the incidence of pertussis has been increasing; however, reports on mixed infection of pertussis with other respiratory pathogens are rare in highly immunized populations. We report the case of a 10-year-old girl who presented with cough, post-tussive emesis, and fever. She was subsequently diagnosed with bronchopneumonia. Although she had received five doses of diphtheria-tetanus-acellular pertussis vaccine, polymerase chain reaction of her nasopharyngeal aspirate confirmed Bordetella pertussis infection. In addition, serologic testing for Mycoplasma pneumoniae was also positive. The patient was treated with roxithromycin without any complications. This is the first report of mixed B. pertussis and M. pneumoniae infection in Korea. To avoid under-diagnosis, pertussis should be considered in patients with chronic cough even when other respiratory pathogens have been documented.

Clinical Manifestations, Management, and Natural Course of Infants with Recurrent Bronchiolitis or Reactive Airways Disease / 소아감염

PURPOSE: The purpose of this study was to investigate the clinical manifestations and 5-year natural course of recurrent bronchiolitis or reactive airways disease (RAD) in infants. METHODS: We reviewed the medical records of infants with recurrent bronchiolitis from January 2007 to December 2007 at The Catholic University of Korea St. Mary's Hospital in Incheon, South Korea. Additionally, we telephoned their parents to confirm their present medical statuses. RESULTS: Sixty-three subjects with recurrent bronchiolitis were identified. The mean age at admission was 8.1 months and the number of males was 44 (69.8%). Of the 63 infants with recurrent bronchiolitis, inhaled corticosteroids, bronchodilators, and antibiotics were given to 62 (98.4%), 53 (84.1%), and 40 (63.5%), respectively. Among the total 63 subjects, we were able to contact the parents of 45 children by telephone. None of these children had been hospitalized during the previous one year period due to respiratory infections or for other medical reasons. Of the 45 subjects we were able to contact, 38 (84.4%) had not experienced any further respiratory difficulties at all. Five (11.1%) had been diagnosed with allergic rhinitis while two (4.4%) were being managed for asthma. CONCLUSION: Most children who presented with recurrent episodes of bronchiolitis in infancy did not show any further respiratory difficulties after five years of age.

Outcome of acute respiratory distress syndrome in children: a single center study

PURPOSE: This study aimed to determine the incidence, etiology, prognostic factors, and outcome of acute respiratory distress syndrome (ARDS) in children and to provide epidemiological data of children with ARDS treated at the pediatric intensive care unit (PICU) of a single center in Korea. METHODS: We conducted a retrospective medical chart review of 19 children diagnosed with ARDS at the PICU of The Catholic University of Korea, Seoul St. Mary's Hospital, between March 2009 and February 2012. RESULTS: Of the 334 PICU patients, 19 (5.6%) satisfied the American-European Consensus Conference definition of ARDS. Thirteen patients with ARDS died (mortality rate, 68.4%). Pneumonia was the most common cause of ARDS and observed in 10 patients (52.6%). There were significant differences between survivors and nonsurvivors in the PaO2/FiO2 ratio and the number of organ failure. The mortality rate was significantly higher in patients with a baseline PaO2/FiO2 ratio 100 mmHg (84.6% vs. 33.3%, P=0.046). We observed that a higher number of organ failure during the PICU stay, resulted in a higher mortality rate (P=0.037). Multiple logistic regression analysis showed that the PaO2/FiO2 ratio (adjusted odds ratio, 0.958) was independently associated with the increased risk of death after controlling for the number of organ failure. CONCLUSION: The mortality rate of ARDS in children was 68.4% in this study, a higher rate than those reported in other national and international studies. The PaO2/FiO2 ratio at the time of ARDS onset was a helpful prognostic factor for predicting the mortality rate of children with ARDS.

Readmission risk factors for children admitted to pediatric intensive care unit with respiratory tract disease

PURPOSE: Children admitted to pediatric intensive care unit (PICU) with respiratory tract disease, often have a tendency to be readmitted to PICU with disease progression. We studied the risk factors for readmission to PICU, with respiratory disease progression. METHODS: Among 286 children admitted to Seoul St. Mary's Hospital PICU from April 2009 to March 2012, 129 children admitted with respiratory tract disease were enrolled. We grouped the children readmitted to PICU with respiratory tract disease progression within 2 weeks (readmission group), and the others (control group). We compared basic and respiratory tract disease characteristics at initial PICU admission between them, by retrospective chart review. RESULTS: Among 129 children, 8 were included in the readmission group, and 121 in the control group. Mortality and underlying disease incidence were higher in the readmission group (P=0.003 and P=0.033, respectively). The readmission group showed higher parenchymal lung disease incidence, and lower initial saturation by pulse oxymeter (SpO2)/fraction of inspiratory oxygen (FiO2), despite underlying disease influence (P=0.035 and P=0.041, respectively). Logistic regression on the underlying disease and respiratory variables showed no single factor with a significantly independent influence on readmission, but parenchymal lung disease had more independent influence. CONCLUSION: For PICU readmission with respiratory tract disease progression, parenchymal lung disease and lower initial SpO2/FiO2 can be a risk factor despite underlying disease influence. Underlying disease and each respiratory characteristic were not significantly independent risk factors, suggesting a correlation of factors. But, parenchymal lung disease can be a more independent risk factor.