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

ABSTRACT

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.