The effect of atopy and allergic diseases on pulmonary function of Korean adolescents

PURPOSE: Pulmonary function test (PFT) plays a key role in the diagnosis and management of asthma in adolescents. But, it is not clear whether adolescents with asthma have significantly reduced lung function when compared with adolescents without asthma. The purpose of this study was to determine the effect of atopy and allergic diseases on pulmonary function and bronchial hyperresponsiveness (BHR) in Korean adolescents. METHODS: A questionnaire survey was conducted on 647 middle school students (male, 264; female, 383) from Seoul city to determine the prevalence of symptoms and diagnosed allergic diseases. We also performed the PFT, methacholine challenge test, skin prick tests and serum total immunoglobulin E. Current atopic dermatitis was diagnosed by doctor's medical examination. RESULTS: Female showed higher values of forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) and higher numbers of BHR (PC20 less than 25 mg/dL) compared to male (P<0.01). BHR was more common in atopy group (P<0.01), but PFT was not significant difference between atopy and nonatopy. Mean values for all spirometric parameters for asthmatic adolescents were in the normal range. Adolescents with asthma symptoms had slightly lower FEV1/FVC and forced expiratory flow 25%-75% than that of adolescents with no history of wheeze ever, asthma diagnosis and current asthma, but there was no statistically significance. CONCLUSION: The majority of adolescents recruited from the general population who reported having asthma symptoms or other allergic diseases had normal lung function. Sex, atopy, and current atopic dermatitis may affect BHR in Korean adolescents.

Vitamin D insufficiency is associated with food sensitization in children under 2 years with atopic dermatitis

PURPOSE: Vitamin D levels are known to be associated with development of allergic diseases. However, existing data are controversial. The aim of this study was to investigate whether vitamin D levels are associated with food sensitization (FS) in young children with atopic dermatitis (AD). METHODS: We performed a medical record review of all patients under 2 years presenting to pediatric allergic clinic in Hallym University Sacred Heart Hospital for atopic dermatitis between March 1, 2012 and February 28, 2013. Serum 25-hydroxyvitamin D (25(OH)D)levels and six specific immunoglobulin E (IgE) to common food allergens were measured in 132 young children with AD. We defined vitamin D insufficiency was 25(OH)D or =0.35 IU/mL to any of six common food allergens. Associations between serum 25(OH)D levels and FS were examined by using multiple logistic regression, adjusting for potential risk and confounding factors. RESULTS: The mean age was 10.1 months. Among the 132 children with AD, 65.9% had FS. In this group, there was a negative correlation between 25(OH)D levels and serum eosinophil percentage (correlation coefficient [r]=-0.335, P<0.01), but not correlated with serum total IgE levels. Children with vitamin D insufficiency were more likely to have FS (adjusted odds ratio, 17.1; 95% confidence interval, 1.36 to 215; P=0.028) than those with adequate vitamin D levels. CONCLUSION: Vitamin D insufficiency is associated with FS in young children with AD. Further research is needed to confirm these findings.