Objective:To investigate the efficacy of montelukast sodium combined with methylprednisolone in the treatment of pediatric allergic purpura and its effects on inflammatory factors and immune function.Methods:A total of 94 children with allergic purpura who received treatment in Taizhou Women and Children's Hospital and Taizhou Hospital Medical Center (Group) Enze Hospital from March 2019 to March 2021 were included in this study. They were randomly divided into observation and control groups ( n = 47/group). The control group was treated with methylprednisolone. The observation group was treated with montelukast sodium combined with methylprednisolone. The course of treatment was 2 weeks in both groups. Efficacy and changes in inflammatory factors and immune function post-treatment relative to those pre-treatment were compared between the two groups. Results:Total response rate in the observation group [93.62% (44/47)] was significantly higher than that in the control group [74.47% (35/47), Z = 2.15, P < 0.05)]. After treatment, interleukin (IL-4), IL-6, and IL-18 levels in each group were significantly decreased compared with those before treatment ( tobservation group = 21.19, 22.26, 27.20, tcontrol group = 11.10, 13.21, 14.86, all P < 0.05). After treatment, IL-4, IL-6, and IL-8 levels in the observation group were (48.98 ± 5.21) ng/L, (34.10 ± 6.42) ng/L, and (53.29 ± 5.67) ng/L, respectively, which were significantly lower than (65.38 ± 7.08) ng/L, (47.83 ± 4.71) ng/L, (67.83 ± 7.10) ng/L in the control group ( t = 12.79, 11.82, 10.97, all P < 0.05). After treatment, CD3 +, CD4 +, and CD4 +/CD8 + in each group were significantly increased compared with those before treatment ( tobservation group = 14.27, 14.41, 17.61, tcontrol group = 6.90, 5.12, 7.40, all P < 0.05). After treatment, CD3 +, CD4 +, and CD4 +/CD8 + in the observation group were (68.94 ± 2.89)%, (39.94 ± 2.15)%, and (1.79 ± 0.13), respectively, which were significantly higher than (63.86 ± 3.28)%, (35.65 ± 2.31)%, and (1.53 ± 0.16) in the control group ( t = 7.96, 9.32, 8.64, all P < 0.05). After treatment, serum IgG and IgM levels in each group were significantly decreased compared with those before treatment ( tobservation group = 21.00, 7.99, tcontrol group = 8.38, 5.76, both P < 0.05). After treatment, serum IgG and IgM levels in the observation group were (1.43 ± 0.19) g/L and (9.74 ± 0.78) g/L, respectively, which were significantly lower than (1.95 ± 0.37) g/L and (10.89 ± 0.85) g/L in the control group ( t = 8.57, 6.83, both P < 0.05). Conclusion:Montelukast sodium combined with methylprednisolone is highly effective on allergic purpura in children. The combined therapy can reduce inflammatory responses and improve immune function in children.