Kee-Jae Lee

Prevalence of immediate-type food allergy in Korean schoolchildren: a population-based study.

Although the prevalence and causes of food allergy (FA) vary by geographic location, large well-designed epidemiological studies in Asia are lacking. The purpose of this study was to evaluate the prevalence of immediate-type FA in the general population of Korean schoolchildren. A population-based, cross-sectional study was conducted in 2010 using a stratified two-stage cluster-sampling design. In this survey, children aged 6-7 years and 12-13 years were randomly selected, and the presence of FA was determined by a questionnaire survey and assessment of specific IgE. After adjustment for missing data, 3907 children aged 6-7 years and 3975 students aged 12-13 years who completed the questionnaire were included in this study. In children aged 6-7 years, the prevalence of confirmed immediate-type FA was 0.3%, and the prevalence of possible immediate-type FA was 0.3%. By contrast, 0.6 and 1.0% of children aged 12-13 years had confirmed immediate-type FA and possible immediate-type FA, respectively. In 6- to 7-year-old children, egg was the most frequent causative food associated with a confirmed or possible immediate-type FA. In 12- to 13-year-old children, crustaceans were the most frequent cause of confirmed immediate-type FA, and fruit was most frequently involved in possible immediate-type FA. This is the first nationwide population-based study of FA in Korean schoolchildren. Unlike in western countries, the prevalence of immediate-type FA seems to be low. In 12- to 13 year-old children with confirmed immediate-type FA, peanuts/tree nuts are not common causes, whereas crustaceans are frequent triggers.

Risk factors of atopic dermatitis in Korean schoolchildren: 2010 international study of asthma and allergies in childhood.

BACKGROUND & OBJECTIVE We aimed to analyse the risk factors of atopic dermatitis (AD) in Korean schoolchildren in 2010. METHODS A nationwide, cross-sectional study was conducted in children aged 6-7 years and adolescents aged 12-13 years who were randomly selected. Information was obtained through a Korean version of the International Study of Asthma and Allergies in Childhood questionnaire (ISAAC), and skin prick tests were performed. AD-diagnosed children were selected for risk factor analysis by using logistic regression. RESULTS We enrolled 4,003 children (M/F = 2,021/ 1,982) in aged 6-7 years and 4,112 children (M/F = 2,029/2,083) in 12-13 years. In children aged 6-7 years, the lifetime prevalence of AD diagnosis was 35.6% (N = 1,424). On the other hand, in the 12 to 13 year age group, the lifetime prevalence of AD diagnosis was 24.2% (N = 981). In the univariate logistic regression analysis in 6-7 year-old children, possible risk factors were atopy, a parental history of allergic disease, the use of antibiotics during infancy, a history of having moved into a newly built house during infancy, the presence of visible mould in the house, and remodelling of house within 12 months. The statistical significance persisted after adjustment. However, antibiotic use during infancy and remodelling within 12 months showed no statistical significance as a risk factor for AD. In contrast, multivariate logistic regression analysis in adolescents demonstrated that female sex, atopy, a parental history of allergic diseases, the presence of visible mould in the house, and a history of having moved into a newly built house during infancy was associated with AD. There was no significant association between AD and other risk factors. CONCLUSION In Korean schoolchildren, risk factors such as atopy, the presence of parental allergic diseases, moving into a newly built house during infancy and visible mould in the house were associated with AD.

Prevalence of Immediate-Type Food Allergy in Korean Schoolchildren in 2015: A Nationwide, Population-based Study

Purpose This study aimed to determine the prevalence of immediate-type food allergy (FA) among schoolchildren in Korea. Methods A nationwide, cross-sectional study was performed in September 2015. A stratified random sample of 50,000 participants was selected from children and adolescents aged 6-7 years (n=17,500), 9-10 years (n=17,500), 12-13 years (n=7,500), and 15-16 years (n=7,500). Parents were asked to complete a questionnaire on the detailed history of immediate-type FA. Results A total of 32,001 (64.0%) responded to the questionnaire survey, and 29,842 children (59.7%) were analyzed after adjusting for missing data. The number of the cases in each age group was 9,671 (6-7 years), 9,756 (9-10 years), 5,169 (12-13 years), and 5,246 (15-16 years). The prevalence of lifetime perceived FA was 15.82%. The prevalence of current immediate-type FA was 4.06% in total, with 3.15% in 6- to 7-year-olds, 4.51% in 9- to 10-year-olds, 4.01% in 12- to 13-year-olds, and 4.49% in 15- to 16-year-olds. Among individual food items, peanut (0.22%) was the most frequent causative food, followed by hens egg (0.21%), cows milk (0.18%), and buckwheat (0.13%). Among the food groups, fruits (1.41%), crustaceans (0.84%), tree nuts (0.32%), and fish (0.32%) were the most common offending foods. The prevalence of food-induced anaphylaxis was 0.97%. The most frequent causative food of anaphylaxis was peanut (0.08%), followed by cows milk (0.07%), buckwheat (0.06%), and hens egg (0.06%), while fruits (0.28%), crustaceans (0.18%), tree nuts (0.12%), and fish (0.09%) were the most commonly responsible food groups. Conclusions The prevalence of current immediate-type FA and food-induced anaphylaxis in Korean schoolchildren in 2015 was 4.06% and 0.97%, respectively. Peanuts, cows milk, hens egg, fruits, crustaceans, and tree nuts are common allergens.

Do newly built homes affect rhinitis in children? The ISAAC phase III study in Korea

As Korea has experienced rapid economic development, the lifestyles of Koreans have become more Westernized, in terms of urbanization and dietary habits. Also, the prevalences of allergic diseases, such as rhinitis, asthma, and dermatitis, have increased rapidly. This study aimed to identify the factors influencing the symptoms of rhinitis conditions, including rhinitis, allergic rhinitis, overlapped rhinitis, and overlapped allergic rhinitis, among Korean children aged 6–7 years.

The association between hypovitaminosis D and pediatric allergic diseases: A Korean nationwide population-based study.

BACKGROUND There is still considerable disagreement regarding the role of vitamin D in the development or exacerbation of allergic diseases. OBJECTIVE To investigate the association between serum vitamin D levels and recent symptoms of allergic diseases in elementary schoolchildren. METHODS A nationwide cross-sectional survey was conducted in children ages 6-7 years from 45 randomly selected elementary schools. The presence of atopic dermatitis (AD) or asthma was defined as medical treatment of children for AD or asthma within 12 months of the survey. The presence of allergic rhinitis (AR) was defined as medical treatment for AR during the past 12 months and a positive skin test response. Current AD was defined as confirmed eczema on physical examination. Serum 25-hydroxyvitamin D (25[OH]D) was measured by chemiluminescent immunoassay. RESULTS Questionnaire data and blood samples were collected from 3720 children. The overall prevalence rates of vitamin D insufficiency (20-29 ng/mL) and deficiency (<20 ng/mL) were 64.0% and 18.4%, respectively. For a 1 ng/mL decrease in 25(OH)D, the adjusted odds ratio (aOR) for AR was 1.020 (95% confidence interval [CI], 1.002-1.040) and the aOR for current AD was 1.027 (95% CI, 1.006-1.047). For each 1 ng/mL decrease in 25(OH)D, the aOR for positive skin-prick test reactivity was 1.013 (95% CI, 1.000-1.027). No significant association between vitamin D level and the prevalence of asthma was observed. CONCLUSIONS A high prevalence of vitamin D deficiency and insufficiency was found in Korean elementary schoolchildren, and low vitamin D levels were associated with recent symptoms of AD and AR.

Association of Polysensitization, Allergic Multimorbidity, and Allergy Severity: A Cross-Sectional Study of School Children.

Background: Aeroallergen sensitization is related to the coexistence of allergic diseases, but the nature of this relationship is poorly understood. The aim of this study was to clarify the relationship of polysensitization with allergic multimorbidities and the severity of allergic diseases. Methods: This study is a cross-sectional analysis of 3,368 Korean children aged 6-7 years-old. We defined IgE-mediated allergic diseases based on structured questionnaires, and classified the sensitivity to 18 aeroallergens by logistic regression and the Ward hierarchical clustering method. The relationship of polysensitization (positive IgE responses against 2 or more aeroallergens classes) with allergic multimorbidities (coexistence of 2 or more of the following allergic diseases: asthma, rhinitis, eczema, and conjunctivitis) and severity of allergic diseases was determined by ordinal logistic regression analysis. Results: The rate of polysensitization was 13.6% (n = 458, 95% CI 12.4-14.8) and that of allergic multimorbidity was 23.5% (n = 790, 95% CI 22.0-24.9). Children sensitized to more aeroallergens tended to have more allergic diseases (rho = 0.248, p < 0.001), although the agreement between polysensitization and multimorbidity was poor (kappa = 0.11, p < 0.001). The number allergen classes to which a child was sensitized increased the risk of wheezing attacks (1 allergen: adjusted odds ratio [aOR] 2.22, 4 or more allergens: aOR 9.39), absence from school (1 allergen: aOR 1.96, 3 allergens: aOR 2.08), and severity of nasal symptoms (1 allergen: aOR 1.61, 4 or more allergens: aOR 4.38). Conclusion: Polysensitization was weakly related to multimorbidity. However, the number of allergens to which a child is sensitized is related to the severity of IgE-mediated symptoms.

Indoor environmental factors associated with wheezing illness and asthma in South Korean children: phase III of the International Study of Asthma and Allergies in Childhood

Abstract Background: The relationship between exposure to indoor environmental pollutants and incidence of asthma and wheezing illness in children is unclear. This study aimed to clarify this relationship by identifying the risk factors associated with these conditions in South Korean children aged 6–7 years. Methods: The parents or guardians of 3810 children aged 6–7 years who had participated in the International Study of Asthma and Allergies in Childhood and met the study criteria completed validated questionnaires regarding their childrens asthma and wheezing illness, risk factors and exposure to indoor pollutants. The data were subjected to chi-square and multivariate logistic regression analysis to identify the factors significantly associated with asthma and wheezing illness. Results: Parental history of allergic disease (odds ratio [OR]: 1.729; 95% confidence interval [CI]: 1.447–2.066), living on the basement or semi-basement floor (OR: 1.891; 95% CI: 1.194–2.996) and living in housing that had been remodeled within the last 12 months (OR: 1.376; 95% CI: 1.101–1.720) were found to be significantly associated with wheezing illness. Parental history of allergic disease (OR: 2.189; 95% CI: 1.483–3.231), male sex (OR: 1.971; 95% CI: 1.369–2.838) and positive skin prick test (SPT) result (OR: 1.583; 95% CI: 1.804–3.698) were found to be significantly associated with current asthma. Conclusions: Although the risk factors for current asthma appear to be more related to the non-modifiable risk factors like sex, parental history of allergic diseases, SPT, the two groups are associated with exposure to modifiable indoor environmental factors.

Reference Values and Utility of Serum Total Immunoglobulin E for Predicting Atopy and Allergic Diseases in Korean Schoolchildren

The present study aimed to investigate the distribution of total serum immunoglobulin E (IgE) levels in Korean schoolchildren and to evaluate its utility in the prediction of atopy and allergic diseases. A nationwide, cross-sectional survey was conducted in first grade students from randomly selected elementary and middle schools. Total IgE levels were measured by ImmunoCAP. Skin prick tests were performed for 18 common inhalant allergens to determine the presence of atopy. Children aged 12–13 years and parents of children aged 6–7 years were asked to complete questionnaire assessing allergic diseases. The cut-off levels of total IgE were determined by analyzing receiver operating characteristic curves. The median total IgE level was 86.7 kU/L (range: 1.5–4,523.1) in 3,753 children aged 6–7 years and 94.7 kU/L (range: 1.5–3,000.0) in 3,930 children aged 12–13 years. Total IgE concentrations were higher in children with atopy or allergic diseases than in those without (all P < 0.001). At the cut-off value of 127.7 kU/L, sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were 67.1%, 75.4%, 65.4%, and 76.7%, respectively, in elementary schoolchildren. At the cut-off value of 63.0 kU/L, sensitivity, specificity, PPV, and NPV were 81.9%, 66.6%, 75.0%, and 75.1%, respectively, in middle schoolchildren. PPV and NPV were ≥ 70% when cut-offs of 258.8 kU/L and 38.4 kU/L were used for the diagnosis of atopy in 6–7 year-olds and 12–13 year-olds, respectively. This nationwide population-based study provided the first normal reference ranges of total IgE in Korean schoolchildren.