In this study, we first found that upregulation of leptin and OPN in obese children with AR was correlated with the count and activation (ECP level) of eosinophil inflammation compared with nonobese children with AR or controls, suggesting that obesity may be involved in the regulation of eosinophil through leptin and OPN. This evidence concerns the gene RNASE3 and obesity due to melanocortin 4 receptor deficiency.