Efficacy of sublingual immunotherapy in the treatment of allergic rhinitis in pediatric patients 3 to 18 years of age: a meta-analysis of randomized, placebo-controlled, double-blind trials

Objective: To evaluate the efficacy of sublingual immunotherapy (SLIT) in the treatment of allergic rhinitis in children. Data Sources: A comprehensive search of the EMBASE, MEDLINE, LILACS, and CINAHL databases from January 1966 to February 10, 2006, was performed. Study Selection: Randomized, double-blind, placebo-controlled trials of SLIT in the treatment of allergic rhinitis in patients 18 years or younger were selected. Outcomes measured were symptom scores and rescue medication use. Analysis was performed with standardized mean differences (SMDs) and a random-effects model. Results: Seventy articles were identified and reviewed. Ten studies, published between 1990 and 2004, fulfilled the selection criteria. Five hundred seventy-seven patients were initially included in the studies. Of these patients, 484 (245 SLIT and 239 placebo) had a final clinical evaluation and could be evaluated. A relevant heterogeneity due to widely differing scoring systems was found. Overall, there was a significant reduction in both symptoms (SMD, 0.56, 95% confidence interval, 1.01-0.10; P = .02) and medication use (SMD, 0.76; 95% confidence interval, 1.46-0.06; P = .03) after immunotherapy. The subanalyses performed for treatment duration and type of allergen showed that SLIT for more than 18 months and with pollen extracts was effective compared with SLIT courses shorter than 18 months and with mites. Conclusion: The results of this meta-analysis showed that, compared with placebo, SLIT with standardized extracts is effective in pediatric patients with allergic rhinitis.