Randomized Double-Blind Placebo-Controlled Crossover Study of Efficacy of Pollen Blocker Cream for Perennial Allergic Rhinitis

Abstract

This study evaluates the efficacy and safety of a pollen blocker cream in treatment of perennial allergic rhinitis (PAR) in a Chinese population. A randomized double-blind placebo-controlled, crossover trial was conducted in the Outpatient Department of the Eye, Ear, Nose, and Throat Hospital, Fudan University, Shanghai, China. Patients diagnosed with PAR were randomly assigned to receive pollen blocker cream or placebo, which was applied and evenly distributed to the lower internal nose region three times daily for a total of 30 days. The primary outcome measures for efficacy were nasal symptom scores (NSSs) and quality of life scores (QoLSs). Medication scores and adverse events were also monitored. After application of pollen blocker, the mean NSS fell from 23.1 to 12.4 points, and the QoLSs fell from 83.9 to 53.2 points (p < 0.001). The decrease in NSSs of pollen blocker (10.7) was highly significant compared with the placebo (3.6; p < 0.001). The decrease in QoLSs of pollen blocker was 30.7 compared with 7.1 in the placebo group, and the difference was also significant (p < 0.05). Interestingly, the mean NSS of the placebo group also decreased from 23.7 to 20.1 (p < 0.05). Additionally, the efficacy of pollen blocker was superior to the placebo both in adults and in children. However, there was no significant difference for individual symptoms of rhinorrhea, nasal itching, sneezing, and nasal congestion between the pollen blocker group and placebo group (p > 0.05). Only one mild epistaxis was reported. The pollen blocker was significantly more effective than the placebo in relieving allergy symptoms and improving life quality of PAR in 30 Chinese people.