PURPOSE: The nature of allergic rhinitis (AR) in preschool aged children remains incompletely characterized. This study aimed to investigate the prevalence of AR and its associated risk factors in preschool-aged children and to assess the clinical utility of fractional exhaled nitric oxide (FeNO). METHODS: This general population-based, cross-sectional survey included 933 preschool-aged (3- to 7-year-old) children from Korea. Current AR was defined as having nasal symptoms within the last 12 months and physician-diagnosed AR. RESULTS: The prevalence of current AR in preschool children was 17.0% (156/919). Mold exposure (adjusted odds ratio [aOR], 1.67; 95% confidence interval [CI], 1.15-2.43) and the use of antibiotics (aOR, 1.97; 95% CI, 1.33-2.90) during infancy were associated with an increased risk of current AR, whereas having an older sibling (aOR, 0.52; 95% CI, 0.35-0.75) reduced the risk. Children with current atopic AR had significantly higher geometric mean levels of FeNO compared to those with non-atopic rhinitis (12.43; range of 1standard deviation [SD], 7.31-21.14 vs 8.25; range of 1SD, 5.62-12.10, P=0.001) or non-atopic healthy children (8.58; range of 1SD, 5.51-13.38, P<0.001). The FeNO levels were higher in children with current atopic AR compared with atopic healthy children (9.78; range of 1SD, 5.97-16.02, P=0.083). CONCLUSIONS: Mold exposure and use of antibiotics during infancy increases the risk of current AR, whereas having an older sibling reduces it. Children with current atopic AR exhibit higher levels of FeNO compared with non-atopic rhinitis cases, suggesting that FeNO levels may be a useful discriminatory marker for subtypes of AR in preschool children.
Anti-Bacterial Agents ; Child ; Child, Preschool* ; Cross-Sectional Studies ; Fungi ; Humans ; Korea ; Nitric Oxide ; Odds Ratio ; Prevalence ; Rhinitis ; Rhinitis, Allergic* ; Risk Factors ; Siblings

PURPOSE: Allergic diseases are triggered by Th2-mediated immune reactions to allergens and orchestrated by various immunological factors, including immune cells and cytokines. Although many reports have suggested that childhood is the critical period in the onset of allergic diseases and aging leads to alter the susceptibility of an individual to allergic diseases, age-related changes in various immunological factors in healthy individuals as well as their difference between healthy and allergic children have not yet been established. METHODS: We investigated the ratio of Th1/Th2 cells and the levels of 22 allergy-related cytokines across all age groups in individuals who were classified as clinically non-atopic and healthy. We also examined their differences between healthy and allergic children to evaluate immunological changes induced by the development of allergic diseases during childhood. RESULTS: The Th1/Th2 ratio rose gradually during the growth period including childhood, reaching peak values in the twenties-thirties age group. Th1/Th2 ratios were significantly lower in allergic children than in healthy controls, whereas 14 of 22 cytokines were significantly higher in allergic children than in healthy controls. On the other hand, there were no differences in Th1/Th2 ratios and cytokines between healthy and allergic adolescents. CONCLUSIONS: In this study, age-related changes in Th1/Th2 ratios were found in normal controls across all age groups, and decreases in Th1/Th2 ratio were observed with increasing of 14 cytokines in allergic children. The results of this study may be helpful as reference values for both monitoring immunological changes according to aging in healthy individuals and distinguishing between normal and allergic subjects in terms of immune cells and soluble factors.
Adolescent ; Aging ; Allergens ; Child ; Critical Period (Psychology) ; Cytokines ; Hand ; Humans ; Hypersensitivity ; Immunologic Factors* ; Reference Values

Nitric oxide (NO) is a biologic mediator of various physiologic functions. Recent evidence suggests the clinical utility of fractional exhaled NO (FeNO) as a biomarker for assessing asthma and other respiratory diseases. FeNO methodologies have been recently standardized by international research groups and subsequently validated in several Korean population studies. Normal ranges for FeNO have been reported for various ethnic groups, and the clinical utility has been widely evaluated in asthma and various respiratory diseases. Based on current evidence including most of Korean population data, this position paper aims to introduce the methodological considerations, and provide the guidance for the proper clinical application of FeNO measurements in Korean populations.
Asthma ; Ethnic Groups ; Humans ; Nitric Oxide* ; Reference Values

PURPOSE: Allergic rhinitis (AR) is a common chronic disease. Many factors could affect the development of AR. We investigated early-life factors, such as delivery mode, feeding method, and use of antibiotics during infancy, which could affect the development of AR. In addition, how interactions between these factors and innate gene polymorphisms influence the development of AR was investigated. METHODS: A cross-sectional study of 1,828 children aged 9-12 years was conducted. Three early-life factors and AR were assessed by a questionnaire. Skin prick tests were done. Polymorphisms of TLR4 (rs1927911) and CD14 (rs2569190) were genotyped. RESULTS: Use of antibiotics during infancy increased the risk of AR (aOR [95% CI] 1.511 [1.222-2.037]) and atopic AR (aOR [95% CI], 1.565 [1.078-2.272]). There were synergistic interactions between caesarean delivery, formula feeding, and use of antibiotics in the rate of atopic AR (aOR [95% CI], 3.038 [1.256-7.347]). Additional analyses revealed that the risk for the development of AR or atopic AR subjects with the TLR4 CC genotype were highest when all the 3 early-life factors were present (aOR [95% CI], 5.127 [1.265-20.780] for AR; 6.078 [1.499-24.649] for atopic AR). In addition, the risk for the development of AR or atopic AR in subjects with the CD14 TT genotype were highest when all the 3 early-life factors were present (aOR [95% CI], 5.960 [1.421-15.002] for AR; 6.714 [1.440-31.312] for atopic AR). CONCLUSIONS: Delivery mode, feeding method, and use of antibiotics during infancy appeared to have synergistic interactions in the development of AR. Gene-environment interactions between polymorphism of innate genes and early- life risk factors might affect the development of AR.
Anti-Bacterial Agents ; Child ; Chronic Disease ; Cross-Sectional Studies ; Delivery, Obstetric ; Feeding Methods ; Female ; Gene-Environment Interaction ; Genotype ; Humans ; Immunity, Innate* ; Infant Food ; Rhinitis* ; Risk Factors* ; Skin ; Surveys and Questionnaires

Herpes simplex encephalitis (HSE) is a rare viral encephalitis in adults. A high (70%) mortality rate with serious complications has been reported even after active, appropriate management. The association between HSE and immune suppression is unclear, but there are case reports of cancer patients in which HSE concomitantly developed after whole brain radiation or high-dose steroid treatment. The clinical manifestations and laboratory findings of these patients are atypical compared to the general population. Although brain magnetic resonance images reveal typical HSE findings, cerebrospinal fluid (CSF) analysis might be normal in cancer patients. We report a case of HSE in a 48-year-old male diagnosed with nasopharyngeal cancer and treated with concurrent chemoradiation. This patient had a normal cell count in CSF, but HSE was finally diagnosed from positive polymerase chain reaction test results. After administration of acyclovir and systemic steroid treatment, the patient had a good clinical course with few neurologic sequelae.
Acyclovir ; Adult ; Brain ; Cell Count ; Cerebrospinal Fluid ; Chemoradiotherapy* ; Encephalitis, Herpes Simplex* ; Encephalitis, Viral ; Humans ; Male ; Middle Aged ; Mortality ; Nasopharyngeal Neoplasms* ; Polymerase Chain Reaction

BACKGROUND: Measurement of the plasma adrenocorticotropic hormone (ACTH) level has been recommended as the first diagnostic test for differentiating between ACTH-independent Cushing syndrome (CS) and ACTH-dependent CS. When plasma ACTH values are inconclusive, a differential diagnosis of CS can be made based upon measurement of the serum dehydroepiandrosterone sulfate (DHEA-S) level and results of the high-dose dexamethasone suppression test (HDST). The aim of this study was to assess the utility of plasma ACTH to differentiate adrenal CS from Cushing' disease (CD) and compare it with that of the HDST results and serum DHEA-S level. METHODS: We performed a retrospective, multicenter study from January 2000 to May 2012 involving 92 patients with endogenous CS. The levels of plasma ACTH, serum cortisol, 24-hour urine free cortisol (UFC) after the HDST, and serum DHEA-S were measured. RESULTS: Fifty-seven patients had adrenal CS and 35 patients had CD. The area under the curve of plasma ACTH, serum DHEA-S, percentage suppression of serum cortisol, and UFC after HDST were 0.954, 0.841, 0.950, and 0.997, respectively (all P<0.001). The cut-off values for plasma ACTH, percentage suppression of serum cortisol, and UFC after HDST were 5.3 pmol/L, 33.3%, and 61.6%, respectively. The sensitivity and specificity of plasma ACTH measurement were 84.2% and 94.3%, those of serum cortisol were 95.8% and 90.6%, and those of UFC after the HDST were 97.9% and 96.7%, respectively. CONCLUSION: Significant overlap in plasma ACTH levels was seen between patients with adrenal CS and those with CD. The HDST may be useful in differentiating between these forms of the disease, especially when the plasma ACTH level alone is not conclusive.
Adrenocorticotropic Hormone* ; Cushing Syndrome* ; Dehydroepiandrosterone Sulfate ; Dexamethasone ; Diagnosis, Differential ; Diagnostic Tests, Routine ; Humans ; Hydrocortisone ; Pituitary ACTH Hypersecretion* ; Plasma* ; Retrospective Studies ; Sensitivity and Specificity

PURPOSE: We investigated the effect of siblings on the development of allergic rhinitis (AR) in Korean adolescents. METHODS: A cross-sectional study of adolescents (n=3,271) aged 12 to 15 years was conducted at three middle schools in Seoul. Demographic and disease-related information was obtained through a questionnaire. RESULTS: The mean age of the subjects was 13.9+/-0.8 years comprising 48.7% males and 51.3% females. The percentage of the subjects who had ever been diagnosed with AR by physician was 30.7%. Subjects who had older sibling and who had younger sibling were 45.3% and 44.2% respectively. Subjects with older sibling were less likely to diagnose AR than subjects without older sibling (adjusted odds ratio [aOR], 0.69; 95% confidence interval [CI], 0.57 to 0.84). Subjects with older sibling, even though with family history of allergic disease had protective effect compared to subjects without older sibling (aOR, 0.62; 95% CI, 0.45 to 0.84). Subjects with younger sibling were more likely to diagnose AR than subjects without younger sibling (aOR, 1.23; 95% CI, 1.02 to 1.49). CONCLUSION: These findings suggest that having older sibling is one of the important protective factor for the development of allergic rhinitis and having younger sibling is risk factor for allergic rhinitis in adolescents.
Adolescent ; Aged ; Cross-Sectional Studies ; Female ; Humans ; Male ; Odds Ratio ; Rhinitis ; Rhinitis, Allergic, Perennial ; Risk Factors ; Siblings

PURPOSE: The aim of the present study was to investigate the relationship between three major allergic diseases, asthma, allergic rhinitis (AR), and atopic dermatitis (AD), and psychological and behavioural problems in preschoolers based on a community survey. METHODS: A cross-sectional survey was conducted using a modified International Study of Asthma and Allergies in Childhood questionnaire to determine the prevalence of symptoms and diagnosed allergic diseases, and a Korean version of the Child Behaviour Checklist to assess internalizing, externalizing, and sleep problems among 780 preschoolers. Five-hundred and seventy-five preschoolers with valid data were included in this study. RESULTS: The prevalence of lifetime diagnosis and treatment in the past 12 months was 8.7% and 4.4% for asthma, 24.4% and 19.2% for AR, and 35.1% and 16.6% for AD, respectively. Scores for internalizing and sleep problems were significantly higher in those diagnosed with AR. Preschoolers who had been treated for AD in the past 12 months had higher attention problem and attention-deficit/hyperactivity disorder scores. Sleep problems were more severe in moderate to severe AD compared to control and mild AD groups, categorised according to SCOring index of AD. The severity of sleep problems correlated positively with the percentage of eosinophils in peripheral blood. CONCLUSIONS: Psychological and behavioural problems differed among the three major allergic diseases, weaker association for asthma and stronger association for AR and AD. The results of this study may lead to the identification of potential underlying shared mechanisms common to allergic diseases and psychological and behavioural problems.
Asthma ; Checklist ; Child ; Child, Preschool ; Cross-Sectional Studies ; Dermatitis, Atopic ; Eosinophils ; Humans ; Hypersensitivity ; Prevalence ; Psychometrics ; Rhinitis ; Rhinitis, Allergic, Perennial ; Surveys and Questionnaires

PURPOSE: Childhood allergies are a serious problem, as they may lead to lifetime chronic disease. Determination of total and specific IgE levels is known to be a diagnostic tool for allergic sensitization; however, IgE levels are affected by various factors, such as age, sex, ethnicity, and geographic area. Thus, we evaluated the distribution of total and specific serum IgE levels against seven inhalant allergens in preschool children and examined their association with allergic diseases in Seoul, Korea. METHODS: Total/specific serum IgE determination and skin prick tests for seven common allergens were performed on 509 children aged 3 to 6 years from 16 child care centers in Seoul, Korea. Demographic characteristics were surveyed from parents using a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. A diagnosis of atopic dermatitis was made by physicians. RESULTS: The geometric mean of total IgE was 80.48+/-3.80 kU/L in preschool children. IgE levels were higher in boys (boys, 102.34+/-3.52 kU/L; girls, 62.37+/-3.93 kU/L; P<0.001) and atopic subjects (atopic, 158.00+/-3.35 kU/L; non-atopic, 52.75+/-3.44 kU/L; P<0.001). An increased prevalence of atopy was associated with a high monthly household income (P=0.004) and higher maternal education level (above university-level education; P=0.009), as well as increased total IgE levels (P=0.036). Physician-diagnosed atopic dermatitis was associated with sensitization to inhalant allergens. CONCLUSIONS: Total IgE levels were very high as compared with those in previous reports from other countries. The most common sensitized allergen was Dermatophagoides farinae, and the positive response rate peaked at age 3 years and was maintained thereafter, particularly in boys. Specific IgE levels for seven inhalant allergens varied with age in preschool children. Although further investigations are needed with a broad range of ages and various allergens, the distribution of the total and specific serum IgE levels in preschool children might help to serve as a reference value to diagnose atopy.
Aged ; Allergens ; Asthma ; Child ; Child Care ; Child, Preschool ; Chronic Disease ; Dermatitis, Atopic ; Dermatophagoides farinae ; Family Characteristics ; Humans ; Hypersensitivity ; Immunoglobulin E ; Korea ; Parents ; Prevalence ; Reference Values ; Skin ; Surveys and Questionnaires

This study attempted to calculate and investigate the incidence of hospitalized acute myocardial infarction (AMI) and stroke in Korea. Using the National Health Insurance claim data, we investigated patients whose main diagnostic codes included AMI or stroke during 2006 to 2010. As a result, we found out that the number of AMI hospitalized patients had decreased since 2006 and amounted to 15,893 in 2010; and that the number of those with stroke had decreased since 2006 and amounted to 73,501 in 2010. The age-standardized incidence rate of hospitalized AMI, after adjustment for readmission, was 41.6 cases per 100,000-population in 2006, and had decreased to 29.4 cases in 2010 (for trend P < 0.001). In the case of stroke was estimated at 172.8 cases per 100,000-population in 2006, and had decreased to 135.1 cases in 2010 (for trend P < 0.001). In conclusion, the age-standardized incidence rates of both hospitalized AMI and stroke in Korea had decreased continuously during 2006 to 2010. We consider this decreasing trend due to the active use of pharmaceuticals, early vascular intervention, and the national cardio-cerebrovascular disease care project as the primary and secondary prevention efforts.
Acute Disease ; Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; Female ; Hospitalization/*trends ; Humans ; Incidence ; Infant ; Infant, Newborn ; Male ; Middle Aged ; Myocardial Infarction/*epidemiology ; Patient Readmission ; Republic of Korea/epidemiology ; Sex Factors ; Stroke/*epidemiology ; Young Adult