Determining an Appropriate Time to Start Prophylactic Treatment with Intranasal Corticosteroids in Japanese Cedar Pollinosis

Prophylactic treatment with intranasal corticosteroids is effective for pollen-induced seasonal allergic rhinitis. However, the appropriate time to start this treatment remains unclear. We performed a double-blinded, randomized, placebo-controlled trial. Starting on 1 February 2014, patients with Japanese cedar pollinosis received either fluticasone furoate nasal spray (FFNS) for 8 weeks (Group A: n = 24), placebo nasal spray for 2 weeks followed by FFNS for 6 weeks (Group B: n = 23), or placebo for 4 weeks followed by FFNS for 4 weeks (Group C: n = 23). The primary endpoint was comparison of the total naso-ocular symptom score (TSS). Secondary endpoints including the increment cost effective ratio (ICER) were also determined. Continuous pollen dispersion began on the 24th of February. Therefore, Group A and Group B received 3-weeks and 1-week of prophylactic treatment, respectively, whereas Group C received post-onset treatment. During the peak pollen-dispersal period, significant differences in TSS were seen between the groups, particularly between Group A and C. The ICER of Group B vs. Group C was lower than that of Group A vs. Group C. These results suggest that long-term prophylactic treatment with FFNS is clinically the most potent treatment, whereas short-term prophylactic treatment is cost effective for pollen-induced allergic rhinitis.