Effect of antihistamine eye drops on the conjunctival provocation test with Japanese cedar pollen allergen.

BACKGROUND: Approximately 16.2% of the Japanese population suffer from cedar pollinosis, with various manifestations such as ophthalmic, laryngo-pharyngeal and skin symptoms in addition to nasal symptoms. Thus, the annual pollen season is an agonizing period for patients. No study has reported symptoms and their clinical courses after conjunctival provocation with purified cedar pollen allergen Cry j1 as well as suppression of these allergen-induced ocular symptoms by antihistamine eye drops. METHODS: Nine patients with Japanese cedar pollinosis who had no nasal or ocular symptoms were included in the present study, after obtaining informed consent in writing. 1) Purified cedar pollen allergen Cry j1 was instilled in the left eye and phosphate-buffered saline (PBS) in the right eye as a control. 2) Levocabastine hydrochloride ophthalmic suspension and ketotifen fumarate ophthalmic solution were respectively instilled in the left and right eyes, which were then challenged with the allergen. Ocular symptoms after provocation with the allergen were recorded through the clinical course. RESULTS: Pollen allergen-induced ocular symptoms were itching and hyperemia of the palpebral conjunctiva, and itching lasted for more than 5 hours. Moreover, preadministration of antihistamine eye drops suppressed the increases in the ocular symptom scores, eliminating itching within 1 hour. Allergen provoked not only ocular symptoms but also nasal symptoms in 77.8% of patients. CONCLUSIONS: Preadministration of antihistamine eye drops suppressed the symptoms induced by the allergen, which suggests that this is an effective early therapy for Japanese cedar pollinosis, if it is started before the pollen season. However, self-protection by patients using a mask may not be effective enough to suppress nasal symptoms during the pollen season, requiring them to additionally wear glasses to avoid exposure to the allergen.

[A comparative study between real time monitor KH-3000 and conventional Durham sampler measuring airborne pollen].

Real time monitoring of airborne pollen has gradually increased because monitoring is laborsaving and provides better real-time information. A problem arose, however, due to differences between the KH3000 (Yamato Co. Ltd) monitor and the conventional Durham sampler pointed out in results of airborne pollen monitoring in Wakayama in 2004. We compared the two monitors for airborne pollen in Wakayama in 2004, which less dispersed than usual. The peak monitored by the KH-3000 monitor was not consistent with the prime period of Japanese cedar and cypress pollen dispersion, especially in February and April, although they correlated highly in March. The inconsistency in February is thought to be caused by snow, and that in April by falsely monitoring beech-tree airborne pollen-which is similar in size-in addition to Japanese cedar and cypress pollen. This report points out the need to take these conditions (snow and other plants pollen) into account when a real time monitor is used for collecting pollen information.