목적: Polyvalent mechanical bacterial lysates (PMBLs, Ismigen®) have been used to boost mucosal barrier immunity, preventing severe respiratory infectious diseases. Additionally, PMBLs showed remarkable and sustained efficacy in alleviating seasonal allergic rhinitis (AR) symptoms. However, the effect of PMBLs in perennial AR has been scantly studied. Thus, this study aimed to investigate the clinical efficacy of PMBLs in patients with perennial AR. 방법:Fourteen patients with perennial AR were finally enrolled to this study and treated with PMBLs for three months. Changes of total nasal symptom score (TNSS) and rhinitis specific quality of life questionnaire (RQLQ) score were respectively measured at baseline, one month, two months, and three months visits after administration of PMBLs. 결과:There was statistically significant decrease in TNSS from 1 month after PMBLs treatment and this decrease had sustained until 3 months (baseline 6.88±1.05, 1 month 4.94±1.47, 2 months 3.44±1.38, 3 months 2.00±1.12) (p<0.001). As to rhinorrhea and nasal obstruction, the symptoms showed statistically significant decrease from 1 month after the treatment (p<0.05). As to sneezing and itching sensation, the decrease was statistically significant from 2 months after the treatment (p<0.05). RQLQ score markedly decreased after the treatment for 3 months (p<0.05) 결론:PMBLs treatment for 3 months can be effective on reducing perennial AR symptoms in the aspect of TNSS and RQLQ score. However, this is a preliminary study and the further studies such as the study on large numbers of patients with control and the biologic marker study are needed.