Relationship of airborne pollen count and treatment outcome in Japanese cedar pollinosis patients. Short Title: Pollen count and treatment outcome in pollinosis

Background In Japan, information of daily airborne Japanese cedar pollen counts is made public during pollen season. If symptoms severity and treatment outcome are predictable according to these pollen counts, management of seasonal allergic rhinitis may become more precise. Aims of the study To evaluate the relationship between airborne pollen counts, symptoms severity and treatment outcome in Japanese cedar pollinosis patients. Methods In the randomized study, patients with moderate to most severe Japanese cedar pollinosis were treated with fexofenadine (60 mg BD) or fexofenadine and nasal corticosteroids for 2 weeks. During the same period daily airborne pollen counts were measured. Results One hundred and five adult patients were enrolled. No difference of treatment efficacy was seen among groups. Detailed results of efficacy & safety were previously described elsewhere. In univariate analysis, the mean cumulated amount of airborne pollen exposure for 4 days prior to the study tended to affect symptoms severity (p=0.053) and the mean cumulated amount of airborne pollen during the treatment period tended to show difference among five treatment outcome categories (p=0.066). In multivariate analysis, the mean cumulated amount of airborne pollen exposure for 4 days prior to the study was identified as only significant factor of symptoms severity (p=0.0327) and cumulated amount of airborne pollen during the treatment period (p=0.027) and allergic history (p=0.027) were significant factors of treatment outcomes. No serious adverse effect was reported during the study. Conclusions The amount of airborne pollen may be predictive of both symptoms severity and treatment outcome.