Background <p>The prevalence of allergic rhinitis (AR) in children is increasing worldwide, driving the growing demand for diagnostic biomarkers to improve clinical practice. Peripheral blood inflammatory indices, as easily accessible and measurable parameters, may offer valuable insights into AR. This study aimed to evaluate the association between peripheral blood inflammatory indices and AR in children.</p> Methods <p>We analyzed peripheral blood inflammatory indices in 1,028 children diagnosed with or without AR from Guangdong Women and Children Hospital. Logistic regression and spearman correlation analysis were employed to investigate the association between these indices and AR. Receiver operating characteristic (ROC) curves were used to assess these indices in predicting AR.</p> Results <p>The Systemic Immune-Inflammation Index (SII) values were significantly higher in AR group. The highest quartile of SII was associated with an increased risk of AR (odds ratio (OR) = 4.86) compared to the lowest quartile. In AR children, SII was positively correlated with IgE (<i>r</i> = 0.324, <i>p</i> = 0.002). The IgE × SII index showed the greatest AUC in predicting high-SII/low-EOS AR subtype (AUC: 0.953).</p> Conclusions <p>SII was positively associated with IgE in AR children, and the IgE × SII index demonstrated strong predictive value for AR with low eosinophils count.</p> Impact <p><UnorderedList Mark="Bullet"> <ItemContent> <p>SII is elevated in children with AR.</p> </ItemContent> <ItemContent> <p>SII is positively correlated with IgE but not EOS or %EOS in AR children.</p> </ItemContent> <ItemContent> <p>The combined index SII × IgE exhibited an improved predictive value for high-inflammation/high-atopic AR.</p> </ItemContent> </UnorderedList></p>