Background and Objectives: Allergy to house dust mite is one of the most common causes of allergic rhinitis (AR) in China. We sought to compare the efficacy and safety of a 6-week cluster schedule of specific immunotherapy with that of a 14-week conventional schedule for the treatment of subjects with persistent AR. Methods: The trial was a prospective and randomized study involving 96 patients with persistent AR, aged 14-60 years, who were allergic to Dermatophagoides pteronyssinus. While 48 patients were randomly assigned to the cluster schedule reaching the maintenance dose within 6 weeks, the other 48 were randomly assigned to the conventional schedule reaching the maintenance dose within 14 weeks. Eighty-nine patients completed a 1-year treatment course. While kinetic changes in clinical efficacy and adverse reactions were observed during the treatment, quality of life, cutaneous reactivity and serum-specific immunoglobulin E to Dermatophagoides pteronyssinus were measured before and after treatment. Results: The cluster schedule reduced the time to reach the maintenance dose by 57% and caused mild systemic adverse reactions after 1.0% of injections (6.7% of patients), with no differences in comparison with the conventional schedule. Cluster specific immunotherapy led to decreases in clinical symptoms and earlier use of medication than did the conventional schedule. Similar improvements in quality of life and reduced cutaneous reactivity without significant changes in specific immunoglobulin E were observed in both groups after 1 year. Conclusions: The cluster schedule is a safe alternative to the conventional schedule with the advantage of achieving clinical effectiveness sooner. Copyright (C) 2008 S. Karger AG, Basel