Efficacy and safety of xyloglucan nasal spray in children with allergic rhinitis: A randomized, double-blind, placebo-controlled, crossover study

Background: A tamarind seed extract-based solution containing xyloglucan forms a protective layer over the nasal epithelium. However, there is no previous study evaluating xyloglucan efficacy in children with allergic rhinitis (AR). Objective: To evaluate the safety and efficacy of xyloglucan as an adjunctive treatment for AR in children. Methods: This randomized, double-blind, placebo-controlled crossover study assessed the efficacy of xyloglucan nasal spray in managing AR symptoms in children. Participants 6–18 years with AR were randomized to receive either xyloglucan or placebo in addition to their current AR therapy for 2 weeks, followed by a 2-week washout and crossover to the alternate treatment for 2 weeks. Primary outcomes were changes in visual analog scale scores analyzed using linear mixed models, adjusting for treatment, period, sequence, and compliance. Subgroup analyses included children with moderate symptoms and good compliance. Results: Seventy-nine children with AR were enrolled, median age 10 years (IQR: 8–12). Treatment with xyloglucan was associated with a significantly greater reduction in nasal congestion compared to placebo (β = −1.013, 95% confidence interval [CI], −1.729 to −0.298, P = 0.006). In children with moderate symptoms and good compliance, the effect on nasal congestion was more pronounced (β = −1.588, P = 0.046). Improvements in rhinorrhea, sneezing, and itching were observed but did not reach statistical significance. Both treatments were well tolerated, with only mild adverse events in both groups. Conclusion: Xyloglucan nasal spray, as an adjunct to standard AR treatment, demonstrated potential benefits in alleviating rhinitis symptoms, particularly nasal congestion, in children with AR. This clinical trial was registered with the Thai Clinical Trials Registry (No. TCTR20240318004).