A comparative study of the clinical efficacy of immunotherapy and conventional pharmacological treatment for patients with perennial allergic rhinitis

This study was designed to compare the clinical outcome of prolonged immuno therapy For perennial allergic rhinitis with that of pharmacological treatm ent. Patients with perennial allergic rhinitis due to Dermatophagoides fari nae (D. farinae) were divided into two groups; a pharmacotherapy group and an immunotherapy group. The pharmacotherapy group was treated with conventi onal pharmacological treatment using antihistamine tablets and topical ster oid sprays and the immunotherapy group was treated with D. farinae extracts for 5 successive years. None of symptom scores at enrolment differed signi ficantly between the groups. At 6 months and 1 year after the start of trea tment the rate of decrease in each score was significantly greater in the p harmacotherapy group than in the immunotherapy group. The rate of decrease in sneezing scores, but not in the other scores, at 2 years after the start of treatment was also greater in the pharmacotherapy group than in the imm unotherapy group. However, at 3 years the rate of decrease in any of the sc ores did not differ significantly between groups. The differences between t he groups became clear-cut again after 5 years of treatment, when the rate of decrease in all of the scores was significantly greater in the immunothe rapy group th;ln in the pharmacotherapy group. Therefore, short-term treatm ent with pharmacological agents is probably superior to immunotherapy but, in the long-term, immunotherapy is apparently superior to pharmacological t reatment with respect to clinical efficacy. In addition, prolonged immunoth erapy provided long-term clinical efficacy and might provide a long-standin g cure even after discontinuation of the therapy. In a questionnaire interv iew, approximately half of patients were very satisfied with prolonged immu notherapy, and three-quarters were fairly satisfied or more. Additionally, the magnitude of improvement in nasal stuffiness contributed significantly and exclusively to the patient evaluation of immunotherapp. We propose that prolonged immunotherapy is never inferior to anti-allergenic pharmacologic al treatment and that it is possible to achieve long-term clinical efficacy or long-standing cure even after the discontinuation of immunotherapy, and that patients with perennial allergic rhinitis will be very satisfied with this prolonged therapeutic technique if nasal stuffiness is considerably a lleviated.