A case of hay fever caused by Fleabane pollen, which is distributed widely in kanto district of Japan, was reported. The pollination of the Fleabane, one of the Comporsitae, occurs from May to June in Yokohama City area.
A 14-year-old boy complained of seasonal nasal attack in early summer. He also complained of slight eye itching during these seasons. The patient showed positive reaction to the skin test with the Fleabane pollen extract, and the wheal-and-flare reaction was observed. Ophthalmic provocation test using 1:100 solution was positive and the threshold of positive reaction was 10^-6. PK titer was 4⁷ and serum IgE level was 0.034mg/dl. Three Fleabane pollens (3-colporate types) were found from the patient's nasal discharge. Among 60 cases who recently visted our clinic, 12 cases (20%) showed positive reaction to the skin test with the Fleabane pollen extract.
From the above mentioned results the Fleabane pollen is considered as one of the antigens which cause hay fever in early summer in Japan