Objective To explore the efficacy and clinical significance of single allergen immunotherapy and multiple allergen immunotherapy in polysentitized patients with allergic rhinitis. Methods 60 patients with allergic rhinitis who were sensitized to dust mites and one more allergen in subcutaneous test or seeum specific Ig E test,had been treated for 3 years in the open-label controled study and divided into two groups,one with multiple allergen subcutaneous immunotherapy( SCIT),another with single allergen sub...