Bok Yang Pyun

Epidemiological Change of Atopic Dermatitis and Food Allergy in School-Aged Children in Korea between 1995 and 2000

Little is known about the prevalence of atopic dermatitis and food allergy outside North America and Europe. We evaluated the prevalence of atopic dermatitis and food allergy with the comparison of prevalence between 1995 and 2000 in Korea and evaluated the correlation of prevalence between atopic dermatitis and food allergy. A cross-sectional questionnaire survey was conducted on random samples of schoolchildren 6 to 14 yr at two time points, 1995 and 2000 throughout Korea. The last twelve months prevalence of atopic dermatitis in Korean school-aged children was increased from 1995 to 2000. The twelve-month prevalence of atopic dermatitis and food allergy were higher in Seoul than in any other provincial cities in 1995, but the prevalence of both diseases in Seoul and Provincial Centers became to be similar in 2000. The rate responded to food allergy of children with atopic dermatitis (9.5%) was lower than that of the western countries (60%). And our data demonstrated paternal and maternal allergy history is very significantly correlated to developing atopic dermatitis in their offspring. The further objective evaluations are required to confirm these outcomes because the environmental and risk factors may be different among the countries according to their living cultures.

Predominance of Community-Associated Methicillin-Resistant Staphylococcus aureus Strains Carrying Staphylococcal Chromosome Cassette mec Type IVA in South Korea

ABSTRACT Studies on the molecular epidemiologic characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains have demonstrated their genetic and geographical diversity. In addition, it has been reported that there are genetic differences between community-associated (CA) and health care-associated (HA) MRSA strains. Therefore, we investigated the major epidemiologic characteristics of CA MRSA isolates in South Korea and compared them with those of HA MRSA strains. Distributions of staphylococcal chromosome cassette mec (SCCmec) types and other molecular features, including the Panton-Valentine leukocidin (PVL) gene, were studied in 138 invasive MRSA isolates. Multiplex type IVA SCCmec was identified as the major CA MRSA infection type (53.1%), with a significantly higher prevalence than in HA MRSA (P < 0.001). One major group of type IVA strains carried a larger atypical class B mec element and new subtypes of ccrA2 (96% amino acid homology). The PVL gene was detected in one USA300-like isolate only. Seven major clone types determined by combinational grouping (genetic background SCCmec typing) showed representative patterns of antimicrobial susceptibilities. We concluded that less multi-drug-resistant strains of clone types B-I and D-1 (genetic background, B and D complexes; type IVA SCCmec) predominate in CA MRSA and that international PVL-positive strains have not spread in South Korea as yet.

Humidifier Disinfectant–associated Children’s Interstitial Lung Disease

RATIONALE Beginning in 2006, epidemics of a fatal lung injury of unknown cause in children were observed in Korea every spring. A recent study demonstrated that this type of childrens interstitial lung disease (chILD) is associated with humidifier disinfectant use. OBJECTIVES To determine the clinical characteristics of this type of chILD and to assess whether the nationwide suspension of humidifier disinfectant sales in the autumn of 2011 affected its incidence. METHODS The clinical characteristics of suspected cases between 2006 and 2011 were determined by a nationwide retrospective study. The potential causal relationship with humidifier disinfectants was examined by a prospective surveillance study after humidifier disinfectant sales were suspended. MEASUREMENTS AND MAIN RESULTS In total, 138 children were diagnosed with this type of chILD, which was characterized by rapid progression, high mortality, predominance in the spring season, and a familial tendency. The annual incidence increased in 2011 and then dropped to zero in 2012. The children were on average 30.4 months old. The most frequent symptoms at admission were cough and dyspnea. As the disease progressed, the typical complication was spontaneous air leak. Eighty children (58%) died. Two years after humidifier disinfectant-sale suspension, no more new cases were found. CONCLUSIONS This study suggests that humidifier disinfectant inhalation causes an idiopathic type of chILD that is characterized by spontaneous air leak, rapid progression, lack of response to treatment, and high mortality. Further safety studies must be performed on common environmental compounds, particularly those that enter the human body by an unusual route.

Natural history and risk factors of atopic dermatitis in children.

Atopic dermatitis (AD) is one of the most common inflammatory allergic diseases with pruritic skin lesions particularly in infancy. It is considered to be the first step of atopic march and has variable disease courses. Many children with AD may resolve their AD symptoms with increasing age and may develop respiratory allergies such as asthma and rhinoconjunctivitis at certain ages. Natural course of AD has been supported by many cross-sectional and longitudinal studies in many countries. In general, atopic dermatitis tends to be more severe and persistent in young children, particularly if they have some risk factors including genetic factors. It appears that approximately 40%-70% of childhood AD will get resolved when they reach the age of 6-7 years. However, it is also observed that over half of the children with AD developed respiratory allergy during late childhood.

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.

Lung function in Korean adolescent girls: in association with obesity and the menstrual cycle.

Gender differences in asthma have been observed with a preponderance of boys affected before puberty and girls during and after puberty. The known influences of the menstrual cycle on asthma support a role for female sex hormones on the changing expression of asthma during adolescence. The purpose of this study was to investigate obesity, the menstrual cycle and lung function in adolescent girls. One hundred and three female high school girls (mean age: 15.9±0.8 yr) were enrolled. The investigation was performed using a questionnaire that included history of asthma, the menstrual cycle, other combined allergic disease and obesity. The skin prick and pulmonary function test during menstruation period and non-menstruation period. Analyses of these factors were compared. The forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) was significantly lower in the obese group compared to the non-obese group (99.8±13.8 vs. 107.1±10.2, p=0.03). The FEV1 was significantly lower in the girls during menstruation period than in the girls who were not on menstruation (77.5±10.2 vs. 80.4±8.6, p=0.03). Our results showed that changes of pulmonary function were related to menstrual cycle and obesity in Korean adolescent girls.

The Clinical Usefulness of IgE Antibodies Against Egg White and Its Components in Korean Children

Purpose Egg (egg white) allergies are among the most common food allergies in infants and young children. Serum egg white-specific IgE (sIgE) levels have been shown to be correlated with clinical symptoms, and the predictive decision point of sIgE levels has been proposed and used widely in the clinical setting. However, some patients whose sIgE levels to egg white are higher than the predictive decision point value show no clinical symptoms, and vice versa. This study was conducted to evaluate the clinical usefulness of sIgE antibodies to egg white and its components in the diagnosis of egg allergies. Methods Forty-one patients younger than 2 years of age with no experience of egg intake due to concerns regarding allergies or a non-specific clinical response to eggs were enrolled. Total IgE levels and the levels of IgE antibodies specific for egg white and its components (ovomucoid, ovalbumin, and conalbumin) were measured by ImmunoCAP testing. The clinical response of the subjects was confirmed by an open oral food challenge (OFC). Results Fifteen (71.4%) out of 21 patients in the egg white-sIgE ≥2 kU/L group showed a positive response, while 10 (50.0%) out of 20 patients in the egg white-sIgE <2 kU/L group showed a negative response to the OFC. There were no statistically significant differences in the levels of sIgE antibodies against egg white and its components between the positive and negative open OFC groups. In addition, there were no statistically significant differences in the levels of sIgE antibodies against egg white and its components based on an intra-group analysis. Conclusions Our results show that the sensitivity and specificity of the predictive decision point values for egg white-sIgE antibodies by ImmunoCAP were relatively low in Korean children. In addition, no egg white component predicted the clinical reactivity of the subjects. We suggest that the predictive decision point value for a positive egg oral challenge test by ImmunoCAP should be re-evaluated. Moreover, we suggest that careful personal history recording and challenge tests are necessary for the correct diagnosis of an egg allergy.

Elevation of the index of left ventricular mass during the acute and subacute phase of Kawasaki disease, and its association with indexes of diastolic function.

Our aim was to determine whether the index of left ventricular mass increases during the acute and subacute phase of Kawasaki disease, and to investigate any relationship between this index and clinical and echocardiographic variables. We performed, therefore, a retrospective study of 66 children with Kawasaki disease, having a mean age of 2.85 years, comparing the findings with those obtained from 57 normal controls, having a mean age of 2.99 years. The data from the patients used for comparison was obtained during the acute and subacute phase of the illness, as well as during the phase of convalescence. We performed correlation analysis of the findings during the acute and subacute phase, determining the relationship between the index of left ventricular mass and other variables. The index was higher (p = 0.0461), and the velocity of propagation of left ventricular early diastolic flow was lower (p < 0.0001), during the acute and subacute phase when compared to control values. The index then reduced (p = 0.0001) during the phase of convalescent when compared to the acute and subacute phase. Levels of albumin in the serum (p = 0.0193), peak E velocity (p = 0.0479), and velocity of propagation (p = 0.0360) were found to be related to the index of left ventricular mass. Significant relationships were found between the differences in this index and differences in body weight when findings during the acute and subacute phase were compared to those of the phase of convalescence. The index of left ventricular mass, therefore, is increased during the acute and subacute phase of Kawasaki disease, and is associated with altered diastolic indexes. This elevation may be due to generalized myocardial swelling from acute inflammation and increased vascular permeability. Measuring this index as a potential predictor of diastolic function should be added to studies of cardiac function during the acute and subacute phase of Kawasaki disease.

Age-Based Causes and Clinical Characteristics of Immediate-Type Food Allergy in Korean Children

Purpose Age-based causes and clinical characteristics of immediate-type food allergy (FA) have not been sufficiently studied. Therefore, we investigated age-dependent clinical profiles of FA in Korean children through an extensive multicenter investigation. Methods Using a case report form developed by the authors, a retrospective medical record review was performed of patients (0-18 years old) diagnosed with immediate-type FA between September 2014 and August 2015 in 14 tertiary hospitals in Korea. Results A total of 1,353 children and adolescents, 93% younger than 7 years, were enrolled in the present study, and 1,661 cases of immediate-type FA were recorded in these patients. The 7 major causative foods were cows milk (28.1%), hens eggs (27.6%), wheat (7.9%), walnuts (7.3%), peanuts (5.3%), buckwheat (1.9%), and shrimps (1.9%). Categorizing the patients into 4 age groups revealed that the most common causative food was different for each age group: cows milk (<2 years), walnuts (2–6 years), walnuts (7–12 years), and buckwheat (13-18 years). The onset time of symptoms was less than 10 minutes in 49%, between 10 and 30 minutes in 17%, and between 30 minutes and 2 hours in 34% of cases. Food-induced anaphylaxis was reported in 506 (30.5%) out of 1,661 cases, and the 7 major causes of food-induced anaphylaxis was cows milk (27.5%), hens eggs (21.9%), wheat (11.3%), walnuts (10.5%), peanuts (5.9%), buckwheat (4.2%), and pine nuts (3.0%). The proportion of anaphylaxis was highest in the patients allergic to buckwheat (67.7%), followed by those allergic to pine nuts (57.7%), walnuts (43.8%), wheat (43.5%), and peanuts (34.1%). Conclusions The 5 major causative foods of immediate-type FA in Korean children were cows milk, hens eggs, wheat, walnuts, and peanuts. The distribution of causative foods was considerably distinctive according to different age groups. Anaphylaxis was reported in 30.5% of immediate-type FA cases.

Easy diagnosis of asthma: computer-assisted, symptom-based diagnosis.

Diagnosis of asthma is often challenging in primary-care physicians due to lack of tools measuring airway obstruction and variability. Symptom-based diagnosis of asthma utilizing objective diagnostic parameters and appropriate software would be useful in clinical practice. A total of 302 adult patients with respiratory symptoms responded to a questionnaire regarding asthma symptoms and provoking factors. Questions were asked and recorded by physicians into a computer program. A definite diagnosis of asthma was made based on a positive response to methacholine bronchial provocation or bronchodilator response (BDR) testing. Multivariate logistic regression analysis was used to evaluate the significance of questionnaire responses in terms of discriminating asthmatics. Asthmatic patients showed higher total symptom scores than non-asthmatics (mean 5.93 vs. 4.93; p<0.01). Multivariate logistic regression analysis identified that response to questions concerning the following significantly discriminated asthmatics; wheezing with dyspnea, which is aggravated at night, and by exercise, cold air, and upper respiratory infection. Moreover, the presence of these symptoms was found to agree significantly with definite diagnosis of asthma (by kappa statistics). Receiver-operating characteristic curve analysis revealed that the diagnostic accuracy of symptom-based diagnosis was high with an area under the curve of 0.647±0.033. Using a computer-assisted symptom-based diagnosis program, it is possible to increase the accuracy of diagnosing asthma in general practice, when the facilities required to evaluate airway hyperresponsiveness or BDR are unavailable.