OBJECTIVES: To investigate the efficacy and safety of montelukast sodium (MKS) combined with levocabastine (LEVO) nasal spray in treating pediatric allergic rhinitis and its impact on quality of life (AR). METHODS: A total of 125 pediatric AR patients, diagnosed between September 2022 and September 2024, were enrolled and divided into two groups. The research group (n = 65) received MKS plus LEVO nasal spray, while the control group (n = 60) received LEVO nasal spray alone. Treatment efficacy, safety (assessing xerostomia, headache, and gastrointestinal disturbances), and clinical symptom scores (rhinorrhea, sneezing, nasal obstruction, and nasal pruritus) were evaluated. Additionally, nasal cavity parameters (nasal resistance (NR), minimum cross-sectional area (mCSA), and nasal cavity volume (NCV)), serum inflammatory markers (IL-4, IL-8, IL-10), serum biochemical indices (total immunoglobulin E [TlgE], eosinophil count [EOS], eosinophil cationic protein [ECP]), and quality of life (Rhinoconjunctivitis Quality of Life Questionnaire [RQLQ]) were analyzed. Univariate and multivariate binary logistic regression analyses were conducted to identify factors influencing treatment outcomes. RESULTS: The research group demonstrated significantly higher overall treatment efficacy than the control group (P<
0.05), with a comparable safety profile (P>
0.05). Post-treatment, clinical symptom scores, IL-4, IL-8, TlgE, EOS, ECP levels and RQLQ scores were significantly reduced in the research group compared to the control group (all P<
0.05). Conversely, IL-10 levels were significantly higher in the research group (both P<
0.05). Notably, passive secondhand smoke exposure, IL-10, EOS, and treatment modality were significantly associated with treatment efficacy (all P<
0.05). Binary logistic regression identified passive secondhand smoke exposure (P = 0.035) and EOS (P = 0.036) as independent risk factors for treatment outcomes. CONCLUSIONS: The combination of MKS and LEVO nasal spray demonstrates superior efficacy and safety in pediatric AR treatment, significantly improving patients' quality of life. Moreover, treatment failure is closely linked to passive secondhand smoke exposure and elevated EOS levels.