Methods: Patients with pollinosis attending 11 otorhinolaryngology clinics in Tokyo during part of pollen season (February 18-26) were enrolled and assigned to either an anti-leukotriene agent (pranlukast) or an antihistamine based on their symptoms in the previous year. During three months of treatment, symptoms and quality of life (QOL) were investigated by a mail questionnaire at seven time points (at the start of treatment, and between March 1 and May 15).
Results: Of 150 patients with pollinosis who were registered, analysis was conducted on 144 patients (62 receiving anti-leukotriene therapy and 82 receiving antihistamine therapy), excluding those with incomplete questionnaires. In both groups, scores for symptoms of pollinosis and QOL were low, suggesting that both drugs were effective considering the high pollen levels season (5-9 times higher than the previous year). After defining types of pollinosis by the severity of symptoms (sneezing, rhinorrhea, or nasal blockage), stratified analysis was conducted. This showed that antihistamine therapy was effective for the sneezing/rhinorrhea type and anti-leukotriene therapy was effective for the nasal blockage type, with no difference between the two drugs the combined type. For the nasal blockage type, symptoms and QOL improved faster with anti-leukotriene than antihistamine therapy from the peak to the end of the pollen season. No adverse effects were observed.
Conclusions: When either an anti-leukotriene (pranlukast) or an antihistamine was used for primal therapy of pollinosis, both drugs improved pollinosis symptoms and QOL. Stratified analysis showed that the antihistamine was more effective for the sneezing/rhinorrhea type and the anti-leukotriene was more effective for the nasal blockage type, with no difference in effectiveness for the combined type. Therefore, appropriate drugs for the type of pollinosis should be selected for primal therapy.