Clinical efficacy of respiratory virus detection by using the FilmArray method in children admitted with respiratory infection

Purpose@#Respiratory virus infection is a common cause of hospitalization in children. Rapid testing for respiratory viruses, such as the FilmArray method, can be clinically useful. However, insufficient evidence exists to support its use in standard clinical care. @*Methods@#We retrospectively analyzed data from children under 18 years old who received the multiplex real-time polymerase chain reaction array (multiplex RT-PCR) method in 2017 and by FilmArray respiratory panel (FilmArray RP) in 2018. @*Results@#Between January, 2017 and December, 2018, we reviewed data from 1,480 hospitalized children. The number of children with virus detection in respiratory viral PCR was 523 in the multiplex RT-PCR method and 419 in the FilmArray method. Seasonal virus outbreak patterns were similar to those of Korea Centers for Disease Control and Prevention in both groups. There was no difference between the 2 groups in the mean length of hospital stay. The time from admission to isolation by influenza infection was significantly shorter in the FilmArray group than in the multiplex RT-PCR group among patients who were not diagnosed with influenza infection by rapid antigen test at the time of admission. @*Conclusion@#The use of FilmArray method for respiratory viruses did not diminish length of hospital stay. However, the FilmArray method may quickly detect the prevalence of respiratory infection and aid in clinical treatment. In addition, it was related with a reduced time from admission to isolation by influenza infection in hospitalized children who were not identified with influenza infection by rapid antigen test at the time of admission.

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.

Clinical usefulness of serum procalcitonin to distinguish between viral pneumonia and Mycoplasma pneumonia in children: A multicenter, cross-sectional study

PURPOSE: The aim of this study was to compare the clinical usefulness of serum procalcitonin (PCT) levels in Mycoplasma pneumoniae pneumonia (M. pneumonia) and viral pneumonia in children. METHODS: We retrospectively analyzed the medical records of 348 patients admitted between June 2015 and December of 2015. There were 162 patients with M. pneumonia without virus coinfection (group 1) and 186 patients with viral pneumonia (group 2). All subjects had radiographic evidence of pneumonia with available specimens for both M. pneumonia and viral testing, and levels of serum PCT, white blood cell counts (WBC), neutrophil portion, and C-reactive protein (CRP). Fifty-eight children who performed follow-up sampling at the time of no fever for more than 48 hours were subdivided into group 3 (M. pneumonia with follow-up sampling, n=41) and group 4 (viral pneumonia with follow-up sampling, n=17). RESULTS: No difference was noted in the levels of serum PCT (P=0.168), CRP (P=0.296), WBC (P=0.732), and neutrophil proportion (P=0.069) between groups 1 and 2, after adjusting for age. Serial changes in serum PCT levels between the first and second samples were significant in group 3 (P=0.046). Serial changes in serum CRP levels between the first and second samples were significant in group 4 (P=0.008). CONCLUSION: Serum PCT and CRP levels may change differently after infection according to the etiology of pneumonia.

Abdominal pain without bruising or sign of trauma: pancreatic injuries in children is difficult to predict

Pancreatic injuries due to trauma in children are rare. An early diagnosis is difficult as the signs and symptoms are insidious, but delays in diagnosis can lead to significant complications. We report a case of a child who visited the emergency department with aggravating abdominal pain. The physicians first diagnosed the abdominal pain as being caused by a disease in the emergency department, but the patient was subsequently diagnosed with pancreatic injury. Clinicians should be aware of a possible trauma in children who complain of vague abdominal pain even in the absence of corresponding history.

Clinical features of Mycoplasma pneumonia in comparison with viral pneumoina in children: A multicenter, cross-sectional study

PURPOSE: This study was conducted to compare clinical features between Mycoplasma pneumonia and viral pneumonia. METHODS: We retrospectively analyzed the medical records of 428 patients requiring hospitalization among children younger than 18 years of age in 5 hospitals in Seoul and Gyeonggi-do. There were 131 patients with M. pneumonia and virus coinfection, 167 patients with M. pneumonia without virus coinfection, and 130 patients with viral pneumonia. All subjects had radiographic evidence of pneumonia with specimens available for both M. pneumonia and viral testing. Virus was identified using the polymerase chain reaction assay in a nasopharyngeal or oropharyngeal swab. M. pneumoniae pneumonia was diagnosed serologically. RESULTS: Human rhinovirus was detected in 60.3% (79 of 131) of children with M. pneumonia accompanied by virus coinfection. Respiratory syncytial virus (RSV) was detected in 38.2% (50 of 130) of children with viral pneumonia. The mean age was significantly lower in the viral pneumonia group than in the M. pneumonia group with and without virus coinfection. The sex distribution did not differ significantly among the 3 study groups. The procalcitonin level was higher in viral pneumonia and erythrocyte sedimentation rate level was higher in the M. pneumonia group although no significant difference was found in C-reactive protein level between the M. pneumonia and viral pneumonia groups. CONCLUSION: Clinical features and inflammatory markers between M. pneumonia and viral pneumonia may be useful for the treatment of community-acquired pneumonia.

Serum periostin levels and squamous cell carcinoma-related antigen levels in children with atopic dermatitis

PURPOSE: It was found that periostin and squamous cell carcinoma-related antigens (SCCAs) were strongly interleukin-13-inducible gene products. This study measures the serum periostin and SCCA levels in children suffering from atopic dermatitis (AD) and to evaluate the association between the severity of AD and their values. METHODS: Seventy AD children aged 1 month to 10 years were included in our study. Subjects were characterized as having atopic eczema (AE; n=55) or non-AE (NAE; n=15) by atopic sensitization. Serum SCCA and periostin levels were measured. RESULTS: The serum periostin levels were significantly higher in children with AE than in those with NAE (geometric mean [95% confidence interval]: 80.47 ng/mL [75.06–85.93 ng/mL] vs. 67.45 ng/mL [59.99–75.64] ng/mL, P=0.020). The serum concentrations of both SCCA1 and SCCA2 were significantly higher in children with AE than in those with NAE (geometric mean [95% confidence interval]: 1.401 [1.198–1.643] ng/mL vs. 0.969 [0.723–1.268] ng/mL, P=0.039 for SCCA1) (1.178 [0.974–1.455] ng/mL vs. 0.711 [0.540–0.994] ng/mL, P=0.025 for SCCA2). The serum periostin levels were significantly correlated with disease severity and with peripheral blood eosinophil counts. The SCCA levels were not significantly correlated with disease severity. Both SCCA1 and SCCA2 were significantly correlated with serum periostin levels and blood eosinophil counts. CONCLUSION: Serum periostin levels may be significantly correlated with disease severity and blood eosinophil counts in children with AD. Serum SCCA levels can be significantly correlated with serum periostin levels and blood eosinophil counts in children with AD.

Relationship between atopy and bronchial hyperresponsiveness to indirect stimuli in asthmatic children

PURPOSE: Both atopy and bronchial hyperresponsiveness (BHR) are characteristic features of asthma. Several BHR studies comparing groups of atopic and nonatopic asthmatics have reported conflicting results. The aim of this study was to compare BHR to indirect stimuli, such as mannitol or exercise, between atopic and nonatopic asthmatics in children. METHODS: We performed a retrospective analysis of data from 110 children with asthma, aged 6–18 years using skin prick tests, and serum total and specific IgE levels. Atopy degree was measured using the sum of graded wheal size or the sum of the allergen-specific IgE. Bronchial provocation tests (BPTs) using methacholine were performed on all subjects. BPTs using indirect simuli, including exercise and mannitol, were also performed. RESULTS: Asthma cases were classified as atopic asthma (n=83) or nonatopic asthma (n=27) from skin prick or allergen-specific IgE test results. There was no significant difference in the prevalence of BHR to mannitol or exercise between atopic and nonatopic asthmatics. Atopic asthma had a significantly lower postexercise maximum decrease in % forced expiratory volume in 1 second (FEV1) (geometric mean [95% confidence interval]: 31.9 [22.9–40.9] vs. 14.0 [9.4–18.6], P=0.015) and a methacholine PC20 (provocative concentration of methacholine inducing a 20% fall in FEV1) than nonatopic asthmatics (geometric mean [95% confidence interval]: 1.24 [0.60–1.87] ng/mL vs. 4.97 [3.47–6.47]) ng/mL, P=0.001), whereas mannitol PD15 (cumulative provocative dose causing a 15% fall in FEV1) was not significantly different between the 2 groups. CONCLUSION: There was no significant difference in the prevalence of BHR to mannitol or exercise between atopic and nonatopic asthmatics in children.

Tracheal Bronchus with Persistent Pulmonary Hypertension of the Newborn: A Case Report

Tracheal bronchus is an uncommon anomaly in which an ectopic bronchus originates directly from the supracarinal trachea. It is usually an asymptomatic anatomical variant incidentally found on computed tomography or bronchoscopy. However, it can present with symptoms, such as chronic cough, wheezing, atelectasis, and recurrent pneumonia. We report a case of tracheal bronchus diagnosed in the neonatal period, in which the term baby presented with respiratory distress and persistent pulmonary hypertension of the newborn after birth, but no other congenital anomaly was found on further evaluation.

Drug reaction with eosinophilia and systemic symptom induced in a 9-year-old boy

The drug reaction with eosinophilia and systemic symptom (DRESS) is a severe adverse drug-induced reaction. Acetaminophen is extensively used as an over-the-counter drug as well as a medical therapeutic. In spite of its frequent use, drug eruptions related to DRESS caused by acetaminophen are rare. This case report describes a 9-year-old boy who experienced fever and maculopapular skin rashes after taking acetaminophen. Leukocytosis with marked eosinophilia and slightly elevated levels of liver enzymes were observed. Symptoms resolved after withdrawal of acetaminophen, followed by intravenous methylprednisolone administration. The diagnosis of DRESS induced by acetaminophen was confirmed by an oral challenge test after 2 months. No allergic reactions to ibuprofen were observed.

Plasma secreted phospholipase A2 in asthmatic children: correlation with leptin levels and exercise induced bronchoconstriction

PURPOSE: Dysregulated cysteinyl leukotriene (CysLT) synthesis is prominent in exercise-induced bronchoconstriction (EIB). Secreted phospholipase A2 (sPLA2) plays a key regulatory role in the biosynthesis of CysLTs. We previously found that serum leptin levels correlate with (EIB) in children with asthma. The aim of this study was to address the relationship between plasma sPLA2/leptin levels and EIB. METHODS: Sixty-seven prepubertal children between the ages of 6 and 10 years were included in the study. They were asthmatics with EIB (n=25), asthmatics without EIB (n=21), and healthy subjects (n=21). We measured the plasma sPLA2 and leptin levels. We also performed pulmonary function tests at baseline, after bronchodilator inhalation, and after exercise. RESULTS: The sPLA2 and leptin levels were significantly higher in asthmatics with EIB than in those without and control subjects. In addition, sPLA2 levels were significantly correlated with body mass index (Speraman correlation coefficient r=0.343, P=0.023) and leptin levels (partial correlation coefficient r=318, P=0.033). The maximum decrease in % forced expiratory volume in 1 second after exercise was significantly correlated with both PLA2 levels (r=0.301, P=0.041) and leptin levels (r=0.346, P=0.018). CONCLUSION: The sPLA2 and leptin levels were significantly higher in asthmatics with EIB than in asthmatics without EIB and control subjects. In addition, sPLA2 levels were significantly correlated with leptin levels and EIB in asthmatic children.

Approaches to the diagnosis and management of chronic urticaria in children / 소아과

Most guidelines for chronic urticaria (CU) in infants and children are based on limited pediatric evidence. Current evidence used to guide treatment in children is extrapolated from data focusing on older age groups. CU in children is a different and complex condition than that in adults. Furthermore, there is little published information regarding urticaria in Korean children. The aim of the present article is to review recent research on chronic childhood urticaria and improve the current understanding of its pathogenesis and management. The classification and definition of urticaria in adults also applies to children. CU is defined as a daily occurrence of spontaneous wheals, angioedema, or both for >6 weeks. The precise pathophysiology of CU is unknown and the rates of successful identification of a cause in children with CU vary from 20%-50%. There is no established laboratory test to evaluate the presence of urticaria. The natural course of childhood CU is undetermined, with limited reports discussing long-term outcomes. Second-generation H1 antihistamines are the cornerstone of management, while limited therapeutic drugs are available for adults.

Component-resolved diagnosis using microarray for diagnosing hypersensitivity to raw fruits in birch pollen sensitized children

PURPOSE: Recently, component-resolved diagnosis (CRD) using microarray technology has been introduced to the field of clinical allergy. This study was aimed to investigate the clinical usefulness of microarray-based IgE detection for diagnosing clinical raw fruit allergy in birch pollen-sensitized children. METHODS: Thirty-one children with allergic disease who had been sensitized to pollen were studied. A pollen-sensitized patient was defined as having an allergen-specific history with concomitant positive skin-prick tests (SPTs) to natural allergen extracts or positive allergen-specific IgE. All subjects underwent SPTs for pollen and fruit. In all subjects, specific IgE to pollen and fruit were measured by ImmunoCAP. Specific IgE antibodies to allergen components were determined by a customized allergen microarray (ISAC). RESULTS: Thirteen of the 31 patients (41.9%) had a history of fruit hypersensitivity with positive SPTs. Measuring IgE to allergen components by ISAC, all the 13 patients with fruit hypersensitivity were positive to at least one of Mal d 1, Pru p 1, Pru p 3, Act d 8, and Act d 2 compared to 12 of the 13 patients (92.3%) who had at least 1 positive IgE to fruits (apple, peach, and kiwi) using ImmunoCAP. The sensitivity of ISAC microarray was 100.0% for the diagnosis of fruit hypersensitivity, but its specificity was 27.7% (5/18). The sensitivity of ImmunoCAP was 92.3%, and its specificity was 83.3%. CONCLUSION: The sensitivity of allergen components tested using microarray for the diagnosis of clinical fruit hypersensitivity in children with pollen allergy was high; however, its specificity was low.

Sensitization patterns to common allergens in Korean children younger than 6 years of age presenting with typical symptoms or signs of allergic diseases: a single center study

PURPOSE: Population studies have reported that sensitization to inhalant allergens is rare in young children; however, most subjects in those studies had little or no symptoms or signs highly suggestive of allergic diseases. The aim of the present study was to assess the prevalence of sensitization to inhalant allergens in young children with symptoms and/or signs of allergic disease. METHODS: We analyzed the results of all specific IgE tests performed at our hospital laboratory in children younger than 6 years presenting with symptoms and/or signs highly suggestive of allergic diseases between 2008 and 2013. Specific IgE tests for Dermatophagoides pteronyssinus, Dermatophagoides farinae, Alternaria alternata, German cockroach, cat dander, egg white or egg yolk, milk, peanut, and soybean were performed on 295 children; a specific IgE concentration > or =0.35 or > or =0.2 IU/mL was considered positive. We also compared allergen sensitization rates using the two cutoff values. RESULTS: One hundred eighty-one children (61.4%) were positive to at least 1 allergen tested and 53 children (18.9%) were positive to at least 1 inhalant allergen when a specific IgE concentration > or =0.35 IU/mL was considered positive. The children were more likely to have asthma or allergic rhinitis when they were sensitized to any inhalant allergen, particularly house dust mites. The prevalence of sensitization to inhalant allergens increased with age (P<0.001). There was no significant difference in the prevalence of polysensitization among different age groups, but sensitization to both inhalant and food allergens significantly increased with age. CONCLUSION: Our results suggest that specific IgE tests to common inhalant allergens, particularly the house dust mites, may be considered when performing blood screening tests for young children presenting with symptoms and/or signs of allergic diseases.

Serum leptin levels correlate with bronchial hyper-responsiveness to mannitol in asthmatic children

PURPOSE: Epidemiological data indicate that obesity is a risk factor in asthma, however effects related to obesity and adipokines on airway inflammation and bronchial hyper-responsiveness (BHR) have not yet been demonstrated in the human airway. The aim of this study was to investigate the relationship between serum adipokine levels and BHR to mannitol in asthmatic children. METHODS: Serum adipokine levels were measured and pulmonary function tests were perfomed: baseline, postbronchodilator inhalation, methacholine inhalation, and mannitol inhalation. The response to mannitol was expressed as the dose causing a 15% decrease in forced expiratory volume in one second (FEV1) (PD15), and as the response-dose ratio (RDR) (% fall in FEV1/cumulative dose). RESULTS: Sixty-nine prepubertal children between the ages of 6 and 10 years were participated in the study. They comprised asthmatic children (n=40) and healthy (n=29). Twenty-two subjects (55.5%) with asthma had a positive mannitol bronchial provocation test (BPT) result. The body mass index (BMI) was higher in those asthmatics with positive mannitol BPTs than in asthmatics with negative mannitol BPTs and in the control group (19.30 kg/m2 vs. 17.60 kg/m2 vs. 17.93 kg/m2, P=0.035, P=0.046). Serum leptin levels were also significantly higher in asthmatics with positive mannitol BPTs than in asthmatics with negative mannitol BPTs and in the control group (10.58 ng/mL vs. 5.49 ng/mL vs. 6.75 ng/mL, P=0.002, P=0.016). Leptin values were significantly associated with a PD15 (r=-0.498, P=0.022) and RDR to mannitol (r=0.346, P=0.033) in asthmatic children after adjustment for BMI. CONCLUSION: Serum leptin levels were significantly associated with BHR to mannitol in asthmatic children.

Ratio of Leukotriene E4 to Exhaled Nitric Oxide and the Therapeutic Response in Children With Exercise-Induced Bronchoconstriction

PURPOSE: This study assessed the association between the ratio of leukotriene E4 (LTE4) to fractional exhaled nitric oxide (FENO) in the response of children with exercise-induced bronchoconstriction (EIB) enrolled in a therapeutic trial with montelukast or inhaled corticosteroid (fluticasone propionate [FP]). METHODS: Children aged 6 to 18 years with EIB were randomized in a 4-week, placebo-controlled, double-blinded trial with montelukast or FP. Before and after treatment, treadmill exercise challenges were performed. The LTE4 levels in the induced sputum and urine and the FENO levels were measured in subjects before and 30 minutes after the exercise challenges. The same tests were conducted after treatment. RESULTS: A total of 24 patients completed the study: 12 in the montelukast group and 12 in FP group. Both study groups displayed a similar postexercise maximum decrease in forced expiratory volume in one second (FEV1) before treatment as well as after treatment. However, there were significant differences in the magnitude of change between the two (Delta; -18.38+/-14.53% vs. -4.67+/-8.12% for the montelukast and FP groups, respectively; P=0.021). The Delta logarithmic sputum baseline and postexercise LTE4/FENO ratio were significantly lower in the montelukast group than in the FP group (baseline; -0.09+/-0.21 vs. -0.024+/-0.03, P=0.045; postexercise, -0.61+/-0.33 vs. -0.11+/-0.28, P=0.023). CONCLUSIONS: These data indicate that the efficacy of montelukast for preventing a maximum decrease in FEV1 after exercise is significantly higher than that of FP, and the high LTE4/FENO ratio is associated with a greater response to montelukast than to FP for EIB therapy. These results suggest that LTE4 may play an important role in EIB.

Usefulness of Pleural Adenosine Deaminase in Children for the Differentiation Tuberculous Pleural Effusion from Mycoplasma pneumonia with Pleural Effusion / 소아알레르기및호흡기학회지

PURPOSE: Determination of adenosine deaminase (ADA) in pleural fluid has been suggested as another tool to establish early diagnosis of tuberculous pleural effusion. However, there are few studies concerning its usefulness in children. The objective of this study was to evaluate the utility of the determination of ADA level in pleural fluid for the differential diagnosis between tuberculous pleural effusion (TPE) and Mycoplasma pneumonia with pleural effusion (MP) in children. METHODS: We retrospectively reviewed the clinical records of 13 TPE patients and 21 MP patients with pleural effusion. Also, we analyzed ADA levels, and clinical, biochemical, microbiologic and cytologic findings in the pleural fluid. RESULTS: The pleural fluid of all the subjects revealed exudative rather than transudate characteristics. The mean ADA level in the TPE group was significantly higher than that in the MP group (106.27+/-43.71 IU/L vs. 65.28+/-26.27 IU/L, P=0.003). The area under the curve in receiver operating characteristic analysis was 0.810. With a cut-off level for ADA of 60 U/L, the sensitivity, specificity, positive predictive value, and negative predictive value were 92.3%, 61.9%, 60.0%, and 92.9%, respectively. As many as 38.9% of patients with MP were false-positive with this ADA cut-off setting. CONCLUSION: Although the measurement of ADA activity in pleural fluid can help TPE diagnosis, we should consider that some cases of MP with pleural effusion showed high ADA activities. Accordingly, the utility of the ADA level in pleural fluid for the differentiation of TPE from MP declines and additional relevant studies are required.

The Revised Edition of Korean Calendar for Allergenic Pollens

The old calendar of pollens did not reflect current pollen distribution and concentrations that can be influenced by changes of weather and environment of each region in South Korea. A new pollen calendar of allergenic pollens was made based on the data on pollen concentrations obtained in eight regions nationwide between 1997 and 2009. The distribution of pollen was assessed every day at 8 areas (Seoul, Guri, Busan, Daegu, Jeonju, Kwangju, Kangneung, and Jeju) for 12 years between July 1, 1997 and June 30, 2009. Pollens were collected by using Burkard 7-day sampler (Burkard Manufacturing Co Ltd, UK). Pollens which were stained with Calberla's fuchsin staining solution were identified and counted. Pine became the highest pollen in May, and the pollen concentrations of oak and birch also became high. Ragweed appeared in the middle of August and showed the highest pollen concentration in the middles of September. Japanese hop showed a high concentration between the middle of August and the end of September, and mugwort appeared in the middles of August and its concentration increased up until early September. In Kangneung, birch appeared earlier, pine showed a higher pollen concentration than in the other areas. In Daegu, Oriental thuja and alder produced a large concentration of pollens. Pine produced a large concentration of pollens between the middle of April and the end of May. Weeds showed higher concentrations in September and mugwort appeared earlier than ragweed. In Busan the time of flowering is relatively early, and alder and Oriental thuja appeared earliest among all areas. In Kwangju, Oriental thuja and hazelnut appeared in early February. Japanese cedar showed the highest pollen concentration in March in Jeju. In conclusion, update information on pollen calendar in South Korea should be provided for allergic patients through the website to manage and prevent the pollinosis.

Changes in Sensitization Rate to Weed Allergens in Children with Increased Weeds Pollen Counts in Seoul Metropolitan Area

The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m3/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m3/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop.

Changes in Sensitization Rate to Weed Allergens in Children with Increased Weeds Pollen Counts in Seoul Metropolitan Area

The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m3/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m3/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop.

Nitric Oxide Correlates with Exercise-Induced Bronchoconstriction in Asthmatic Children / 소아알레르기및호흡기학회지

PURPOSE: Exercise-induced bronchoconstriction (EIB) affects daily activities as well as school performance in children. Exhaled nitric oxide (eNO) is a noninvasive test that measures airway inflammation in asthmatics. The aim of this study was to address the relationship between eNO and childhood EIB. METHODS: Our study consisted of 101 children aged 6 to 18 years belonging to one of three groups, asthmatic children with EIB (n=31), asthmatic children without EIB (n=28), or healthy controls (n=42). After children were taken off drugs that treated their asthma, baseline (pre-exercise) eNO and biomarkers of inflammation were measured. All subjects underwent spirometry and the bronchial challenge by methacholine inhalation and outdoor free running. RESULTS: eNO levels in asthmatic children with EIB were significantly greater than those in both asthmatic children without EIB (P=0.012) and controls (P<0.001). The median eNO (interquartile range) levels were 26.0 (15.0 to 46.0) parts per billion (ppb) in asthmatic children with EIB, 16.0 (12.5 to 28.0) ppb in asthmatic children without EIB, and 12.0 (10.0 to 15.3) ppb in controls. Post-exercise decrease of forced expiratory volume in 1 second correlated positively with eNO (r=0.637, P<0.001; r, partial correlation coefficient adjusted for age and height). The cutoff value for prediction of significant EIB was 20 ppb, and the overall sensitivity, specificity, positive predictive value, and negative predictive values were 61.3%, 80.0%, 57.6%, and 82.4%, respectively. The area under the receiver operating characteristic curve was 0.767 (95% confidence interval, 0.661 to 0.874). CONCLUSION: Baseline eNO levels correlate with the post-exercise decrease of forced expiratory volume in 1 second, suggesting that eNO may be a tool in the prediction of EIB.