The effect of early intervention for the patients with Japanese cedar pollinosis by Pranlukast Hydrate in the OHIO Chamber

INTERVENTION: Pranlukast Hydrate capsules are orally administered to 15 subjects at twice daily one month from Feb. 29 through Feb. 01. Japanese cedar pollen exposure mid‐Feb. in OHIO Chamber. Placebo capsules are orally administered to 15 subjects at twice daily one month from Feb. 29 through Feb. 01. Japanese cedar pollen exposure mid‐Feb. in OHIO Chamber. CONDITION: Japanese cedar pollinosis PRIMARY OUTCOME: Nasal symptoms score SECONDARY OUTCOME: 1) No of sneezing; 2) Nasal secretion volume; 3) Occurrence time of the first nasal symptom INCLUSION CRITERIA: 1) CAP‐RAST score against Japanese cedar pollen over class 2 in the past. 2) Have experience with cedar pollen exposure in the OHIO Chamber in the past, patients with nasal symptoms with nasal congestion. 3) Patients who were judged to be suitable for patients enrollment by doctor in screening visit or medical examination results. 4) Written informed consent is required.