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

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

BACKGROUND: We investigated whether patients' perceived glycemic control and self-reported diabetes self-care correlated with their actual glycemic control. METHODS: A survey was administered among patients with diabetes mellitus at an outpatient clinic with structured self-report questionnaires regarding perceived glycemic control and diabetes self-management. Actual glycemic control was defined as a change in glycated hemoglobin (A1C) or fasting plasma glucose (FPG) since the last clinic visit. RESULTS: Patients who perceived their glycemic control as "improved" actually showed a mild but significant decrease in the mean A1C (-0.1%, P=0.02), and those who perceived glycemic control as "aggravated" had a significant increase in the mean FPG (10.5 mg/dL or 0.59 mmol/L, P=0.04) compared to the "stationary" group. However, one-half of patients falsely predicted their actual glycemic control status. Subjective assessment of diabetes self-care efforts, such as adherence to a diet regimen or physical activity, correlated positively with perceived glycemic control but showed no association with actual glycemic control. CONCLUSION: Patients should be encouraged to assess and monitor diabetes self-care more objectively to motivate behavioral modifications and improve their actual glycemic control.
Ambulatory Care ; Ambulatory Care Facilities ; Blood Glucose ; Diabetes Mellitus ; Diet ; Fasting ; Hemoglobin A, Glycosylated ; Humans ; Motor Activity ; Self Care* ; 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

BACKGROUND: Dipeptidyl peptidase-4 (DPP-4) inhibitor add-on therapy is a new option for patients with inadequately controlled type 2 diabetes who are taking combined metformin and sulfonylurea (SU). We evaluated the efficacy and safety of this triple therapy and the characteristics of rapid responders and hypoglycemia-prone patients. METHODS: We included 807 patients with type 2 diabetes who were prescribed a newly added DPP-4 inhibitor to ongoing metformin and SU in 2009 to 2011. Glycemia and other metabolic parameters at baseline, 12, 24, and 52 weeks, as well as episodes of hypoglycemia were analyzed. Rapid responders were defined as patients with > or =25% reduction in glycosylated hemoglobin (HbA1c) within 12 weeks. RESULTS: At baseline, while on the submaximal metformin and SU combination, the mean HbA1c level was 8.4%. Twelve weeks after initiation of DPP-4 inhibitor add-on, 269 patients (34.4%) achieved an HbA1c level < or =7%. Sixty-six patients (8.2%, 47 men) were rapid responders. The duration of diabetes was shorter in rapid responders, and their baseline fasting plasma glucose (FPG), HbA1c, C-peptide, and homeostasis model assessment of insulin resistance were significantly higher. Patients who experienced hypoglycemia after taking DPP-4 inhibitor add-on were more likely to be female, to have a lower body weight and lower triglyceride and FPG levels, and to have higher homeostasis model assessment of beta-cells. CONCLUSION: An oral hypoglycemic triple agent combination including a DPP-4 inhibitor was effective in patients with uncontrolled diabetes. Proactive dose reduction of SU should be considered when a DPP-4 inhibitor is added for rapid responders and hypoglycemia-prone patients.
Blood Glucose ; Body Weight ; C-Peptide ; Diabetes Mellitus, Type 2 ; Dipeptidyl-Peptidase IV Inhibitors ; Fasting ; Female ; Hemoglobin A, Glycosylated ; Homeostasis ; Humans ; Hypoglycemia ; Insulin Resistance ; Metformin* ; Sulfonylurea Compounds ; Triglycerides

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

Allergy diagnosis and immunotherapy in Korea rely mostly on imported allergen extracts. However, some allergens that are not important in Western countries are not commercially available, and even the same species of allergen source often displays differences in allergenicity due to amino acid sequence polymorphisms. Therefore, it is essential to prepare allergen extracts that reflect regional characteristics. Allergen standardization has been performed since 2009 with the support of the Korea Center for Disease Control and Prevention. Here, we summarize the current status of allergen standardization, focusing on the house dust mite and cockroach. Pollen allergens that are under investigation are also briefly described.
Allergens ; Amino Acid Sequence ; Centers for Disease Control and Prevention (U.S.) ; Cockroaches ; Diagnosis ; Hypersensitivity ; Immunotherapy ; Korea ; Pollen ; Pyroglyphidae

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