[The pollen count of Cryptomeria japonica and nasal symptom of Cryptomeria japonica pollinosis patients in recent three years in Mie Prefecture].

Airborne scattering of Cryptomeria japonica pollen depends on climate. Total pollen count and scattering pattern varies from one year to another. We counted Cryptomeria japonica pollen in February and March from 1993 to 1995 at several points in Mie Prefecture. One-third to two-thirds of all the patients who visited our clinic for the first time in the pollen period were occupied by allergic patients. The pollen count in 1995 amounted to 17943/cm2 at Tsu and 99512/cm2 in the whole prefecture, which is the largest in the past 12 years. The number of days in which patients severely suffered was correlated to the pollen count for the past three years. It was shown that nasal symptoms developed after certain amount of pollen had scattered, but the severity of symptoms thereafter largely depended on the total pollen count. At Tsu in 1995, we scarcely had pollen scattering in February but had tremendous amount of pollen count in March. Percentage of development of nasal symptoms among thirty patients was well correlated to the logarithm of accumulated pollen count. When accumulated pollen count reached to 100/cm2, half the patients developed symptoms. Most of the patients developed symptoms when it reached to 1000/cm2. Since there is a great interindivisual difference in when and how much patients have nasal symptoms, the choice of therapy should be based not only on the pollen count but also on the symptom and condition of each patient.