Dong In Suh

A Multicenter Retrospective Case Study of Anaphylaxis Triggers by Age in Korean Children

Purpose Although anaphylaxis is recognized as an important, life-threatening condition, data are limited regarding its triggers in different age groups. We aimed to identify anaphylaxis triggers by age in Korean children. Methods We performed a retrospective review of medical records for children diagnosed with anaphylaxis between 2009 and 2013 in 23 secondary or tertiary hospitals in South Korea. Results A total of 991 cases (mean age=5.89±5.24) were reported, with 63.9% involving patients younger than 6 years of age and 66% involving male children. Food was the most common anaphylaxis trigger (74.7%), followed by drugs and radiocontrast media (10.7%), idiopathic factors (9.2%), and exercise (3.6%). The most common food allergen was milk (28.4%), followed by egg white (13.6%), walnut (8.0%), wheat (7.2%), buckwheat (6.5%), and peanut (6.2%). Milk and seafood were the most common anaphylaxis triggers in young and older children, respectively. Drug-triggered anaphylaxis was observed more frequently with increasing age, with antibiotics (34.9%) and nonsteroidal anti-inflammatory drugs (17.9%) being the most common causes. Conclusions The most common anaphylaxis trigger in Korean children was food. Data on these triggers show that their relative frequency may vary by age.

Serum periostin levels correlate with airway hyper‐responsiveness to methacholine and mannitol in children with asthma

Periostin is a matricellular protein, and its synthesis in airway epithelial cells and lung fibroblasts is induced by interleukin (IL)‐4 and IL‐13. The significance of periostin as a biomarker of TH2‐induced airway inflammation, and (importantly) as a measure of the response to TH2‐targeted therapy, has recently been emphasized. We explored the relationship between periostin and airway hyperresponsiveness (AHR) in asthmatic children.

Bronchial hyperresponsiveness to methacholine and adenosine 5′‐monophosphate, and the presence and degree of atopy in young children with asthma

Cite this as: D. I. Suh, J. K. Lee, C. K. Kim and Y. Y. Koh, Clinical & Experimental Allergy, 2011 (41) 338–345.

Association between cord blood 25-hydroxyvitamin D concentrations and respiratory tract infections in the first 6 months of age in a Korean population: a birth cohort study (COCOA)

Purpose Previous studies suggest that the concentration of 25-hydroxyvitamin D [25(OH)D] in cord blood may show an inverse association with respiratory tract infections (RTI) during childhood. The aim of the present study was to examine the influence of 25(OH)D concentrations in cord blood on infant RTI in a Korean birth cohort. Methods The levels of 25(OH)D in cord blood obtained from 525 Korean newborns in the prospective COhort for Childhood Origin of Asthma and allergic diseases were examined. The primary outcome variable of interest was the prevalence of RTI at 6-month follow-up, as diagnosed by pediatricians and pediatric allergy and pulmonology specialists. RTI included acute nasopharyngitis, rhinosinusitis, otitis media, croup, tracheobronchitis, bronchiolitis, and pneumonia. Results The median concentration of 25(OH)D in cord blood was 32.0 nmol/L (interquartile range, 21.4 to 53.2). One hundred and eighty neonates (34.3%) showed 25(OH)D concentrations less than 25.0 nmol/L, 292 (55.6%) showed 25(OH)D concentrations of 25.0-74.9 nmol/L, and 53 (10.1%) showed concentrations of ≥75.0 nmol/L. Adjusting for the season of birth, multivitamin intake during pregnancy, and exposure to passive smoking during pregnancy, 25(OH)D concentrations showed an inverse association with the risk of acquiring acute nasopharyngitis by 6 months of age (P for trend=0.0004). Conclusion The results show that 89.9% of healthy newborns in Korea are born with vitamin D insufficiency or deficiency (55.6% and 34.3%, respectively). Cord blood vitamin D insufficiency or deficiency in healthy neonates is associated with an increased risk of acute nasopharyngitis by 6 months of age. More time spent outdoors and more intensified vitamin D supplementation for pregnant women may be needed to prevent the onset of acute nasopharyngitis in infants.

A multicenter study on anaphylaxis caused by peanut, tree nuts, and seeds in children and adolescents

Peanut (PN) and tree nuts (TNs) are common causes of anaphylaxis in Western countries, but no information is available in Korea. To feature clinical characteristics of anaphylaxis caused by PN, TNs, and seeds, a retrospective medical record review was performed in 14 university hospitals in Korea (2009–2013). One hundred and twenty‐six cases were identified, with the mean age of 4.9 years. PN, walnut (WN), and pine nut accounted for 32.5%, 41.3%, and 7.1%, respectively. The median values of specific IgE (sIgE) to PN, WN, and pine nut were 10.50, 8.74, and 4.61 kUA/l, respectively. Among 50 cases managed in the emergency department, 52.0% were treated with epinephrine, 66.0% with steroid, 94.0% with antihistamines, 36.0% with oxygen, and 48.0% with bronchodilator. In conclusion, WN, PN, and pine nut were the three most common triggers of anaphylaxis in Korean children, and anaphylaxis could occur at remarkably low levels of sIgE.

Relationship Between Atopy and Bronchial Hyperresponsiveness

Both atopy and bronchial hyperresponsiveness (BHR) are characteristic features of asthma. They are also found among non-asthmatic subjects, including allergic rhinitis patients and the general population. Atopy and BHR in asthma are closely related. Atopy induces airway inflammation as an IgE response to a specific allergen, which causes or amplifies BHR. Moreover, significant evidence of the close relationship between atopy and BHR has been found in non-asthmatic subjects. In this article, we discuss the relationship between atopy and BHR in the general population, asthmatic subjects, and those with allergic rhinitis. This should widen our understanding of the pathophysiology of atopy and BHR.

Methacholine and adenosine 5'-monophosphate (AMP) responsiveness, and the presence and degree of atopy in children with asthma.

To cite this article: Suh DI, Lee JK, Kim CK, Koh YY. Methacholine and adenosine 5′‐monophosphate (AMP) responsiveness, and the presence and degree of atopy in children with asthma. Pediatr Allergy Immunol 2011; 22: e101–e106.

Bronchial hyperresponsiveness in preschool children with allergic rhinitis.

Background Nonasthmatic subjects with allergic rhinitis often have bronchial hyperresponsiveness (BHR), characteristic of asthma. The presence and degree of atopy is suggested to be important for BHR in patients with asthma. We aimed to assess BHR to methacholine (direct stimulus) and to adenosine 5′-monophosphate (AMP; indirect stimulus) in preschool children with allergic rhinitis and to investigate their relationship with the degree of atopy. Methods Methacholine and AMP bronchial challenges were performed in preschool children with allergic rhinitis (n = 96), using a modified auscultation method. The end point concentration, resulting in audible wheezing and/or oxygen desaturation, was determined for each challenge. The degree of atopy was assessed using serum total IgE levels, the number of positive skin-prick tests, and atopic scores (sum of graded wheal size). Results BHR to methacholine (end point concentration, ≤8 mg/mL) and to AMP (end point concentration, ≤200 mg/mL) was observed in 32 (33.3%) and 26 (27.1%) subjects, respectively. No significant relationship was observed between BHR to methacholine and any atopy parameter. In contrast, the atopic scores were higher in the AMP–BHR+ group compared with the AMP–BHR− group, and a significant association was found between the degree of atopic scores and the frequency of BHR to AMP (score for trend, p = 0.006). Such a relationship was not observed for serum total IgE levels and the number of positive SPTs. Conclusion BHR to methacholine and BHR to AMP were detected in a significant proportion of preschool children with allergic rhinitis. The degree of atopy in terms of atopic scores seems to be an important factor for BHR to AMP but not for BHR to methacholine.

Home Mechanical Ventilation in Childhood-Onset Hereditary Neuromuscular Diseases: 13 Years’ Experience at a Single Center in Korea

Introduction Children with hereditary neuromuscular diseases (NMDs) are at a high risk of morbidity and mortality related to respiratory failure. The use of home mechanical ventilation (HMV) has saved the lives of many children with NMD but, due to a lack of studies, dependable guidelines are not available. We drew upon our experience to compare the various underlying NMDs and to evaluate HMV with regard to respiratory morbidity, the proper indications and timing for its use, and to develop a policy to improve the quality of home noninvasive ventilation (NIV). Methods We retrospectively analyzed the medical records of 57 children with childhood-onset hereditary NMDs in whom HMV was initiated between January 2000 and May 2013 at Seoul National University Childrens Hospital. The degree of respiratory morbidity was estimated by the frequency and duration of hospitalizations caused by respiratory distress. Results The most common NMD was spinal muscular atrophy (SMA, n = 33). Emergent mechanical ventilation was initiated in 44% of the patients before the confirmed diagnosis, and the indicators of pre-HMV respiratory morbidity (e.g., extubation trials, hypoxia, hospitalizations, and intensive care unit stay) were greater in these patients than in others. The proportion of post-HMV hospitalizations (range, 0.00−0.52; median, 0.01) was lower than that of pre-HMV hospitalizations (0.02−1.00; 0.99) (P < 0.001). Eight patients were able to maintain home NIV. The main causes of NIV failure were air leakage and a large amount of airway secretions. Conclusions The application of HMV helped reduce respiratory morbidity in children with childhood-onset hereditary NMD. Patients with SMA type I can benefit from an early diagnosis and the timely application of HMV. The choice between invasive and noninvasive HMV should be based on the patient’s age and NIV trial tolerance. Systematic follow-up guidelines provided by a multidisciplinary team are needed.

Airway refractoriness to inhaled mannitol after repeated challenge

Exercise and inhaled mannitol are thought to cause bronchoconstriction through a similar mechanism in asthma. The response to exercise becomes refractory with repeated challenges. This study aimed to investigate whether repeated challenge with mannitol induces refractoriness, as with exercise.