Efficacy of Pranlukast in subjects with Japanese Cedar pollinosis in the OHIO Chamber

INTERVENTION: Two pranlukast capsules are orally administered after the meal 4 times ( 2 times before the exposure and 2 times after the exposure ). The study consists of 2 times exposure in OHIO Chamber at one week intervals. Two placebo capsules are orally administered after the meal 4 times ( 2 times before the exposure and 2 times after the exposure ). The study consists of 2 times exposure in OHIO Chamber at one week intervals. CONDITION: Japanese cedar pollinosis PRIMARY OUTCOME: nose and eye symptoms SECONDARY OUTCOME: the number of sneezing, the amount of nasal secretion, the manifestation time of nasal symptoms, nasal airway resistance, respiratory function and performance test( D‐CAT ) INCLUSION CRITERIA: 1) Subjects must have at least a 2‐year history of allergic symptoms during the Japanese cedar pollen season, such as sneezing, nasal discharge and nasal obstruction. 2) Subjects must have had blood tests within a 3 years showing positive CAP‐RAST scores ( between 2 and 6 ) for Japanese cedar pollen. 3) Subjects must be appropriate to this study by the judgment of doctor. 4) Informed consent must be obtained from the subjects prior to study entry.