Clinical effects of immunotherapy on Japanese cedar pollinosis in the season of cedar and cypress pollination.

Because of cross-allergenicity between Cryptomeria japonica (Japanese cedar) and Chamaecyparis obtusa (Japanese cypress) pollens, many Japanese cedar pollinosis patients have symptoms during the cypress pollination season. Therefore, the effect of immunotherapy (IT) specific for Japanese cedar pollinosis must be evaluated not only in the cedar season but also in the cypress season. Eight out of 16 patients with cedar pollinosis who received IT and the same number not receiving IT (non-IT) was studied. Nasal and ocular symptoms and medication(s) prescribed were classified from score 0 to 4 and score 0 to 3, respectively. The sum of these scores was used as the symptom-medication score (SMS). IT with Japanese cedar pollen extract reduced the daily SMS not only in cedar but also in the cypress pollination season, but not significantly. However, after the season, the mean SMS in the IT group tended to be lower than that in the non-IT group (P < 0.1). In conclusion, IT was useful as well as concomitant medications also in the cypress season, and considered to shorten the long-drawn symptoms persisting after the season.