Sensitization patterns to common allergens in Korean children younger than 6 years of age presenting with typical symptoms or signs of allergic diseases: a single center study

PURPOSE: Population studies have reported that sensitization to inhalant allergens is rare in young children; however, most subjects in those studies had little or no symptoms or signs highly suggestive of allergic diseases. The aim of the present study was to assess the prevalence of sensitization to inhalant allergens in young children with symptoms and/or signs of allergic disease. METHODS: We analyzed the results of all specific IgE tests performed at our hospital laboratory in children younger than 6 years presenting with symptoms and/or signs highly suggestive of allergic diseases between 2008 and 2013. Specific IgE tests for Dermatophagoides pteronyssinus, Dermatophagoides farinae, Alternaria alternata, German cockroach, cat dander, egg white or egg yolk, milk, peanut, and soybean were performed on 295 children; a specific IgE concentration > or =0.35 or > or =0.2 IU/mL was considered positive. We also compared allergen sensitization rates using the two cutoff values. RESULTS: One hundred eighty-one children (61.4%) were positive to at least 1 allergen tested and 53 children (18.9%) were positive to at least 1 inhalant allergen when a specific IgE concentration > or =0.35 IU/mL was considered positive. The children were more likely to have asthma or allergic rhinitis when they were sensitized to any inhalant allergen, particularly house dust mites. The prevalence of sensitization to inhalant allergens increased with age (P<0.001). There was no significant difference in the prevalence of polysensitization among different age groups, but sensitization to both inhalant and food allergens significantly increased with age. CONCLUSION: Our results suggest that specific IgE tests to common inhalant allergens, particularly the house dust mites, may be considered when performing blood screening tests for young children presenting with symptoms and/or signs of allergic diseases.

Effects of plasma endotoxin concentrations on the severity of atopic dermatitis in children

PURPOSE: Endotoxin exposure is associated with the development and pathogenesis of allergic diseases. The present study aimed to determine whether plasma endotoxins are elevated in children with atopic dermatitis (AD) and whether the plasma endotoxins are associated with the AD severity. METHODS: This study included 42 children with AD and 16 controls. The AD severity was assessed and skin prick tests were performed along with serum total IgE, total eosinophil count, and ImmunoCAP analyses for common allergens. For plasma endotoxin levels, kinetic turbidimetric assay and limulus amebocyte lysate reagent were used. RESULTS: The endotoxin levels were significantly higher in children with AD than in controls (0.039 [interquartile range {IQR}, 0.031 to 0.046] EU/mL vs. 0.031 [IQR, 0.019 to 0.035] EU/mL, P<0.05). The endotoxin levels showed a significantly inverse correlation with the disease severity in the extrinsic AD (r=-0.414, P=0.017) but not in the intrinsic AD (r=0.222, P=0.426). No significant correlation was observed between plasma endotoxin levels, serum total eosinophil count, and serum total IgE. CONCLUSION: Our results suggest that plasma endotoxin level is increased in the AD subjects than in the normal controls and affects the disease severity only in the extrinsic AD subjects. Further studies with larger sample sizes are warranted to investigate whether plasma endotoxin levels have a different effect on the AD severity depending on the presence of atopy.