An epidemiological examination was carried out on 330 farmers engaged in pear and apple cultivation. First, all examinees answered questions about the presence of allergic symptoms. To those who have had any allergic symptoms, the intradermal skin reaction tests with pollen extracts (Japanese pear, apple, cedar and orchard grass) and house dust were performed.
The results were as follows:
1. 35.8% of all examinees manifested some allergic symptoms during the bloom of pear and apple (from April to May).
2. Nasal or ocular symptoms were observed in 28.5% and 27.3% respectively. About three-fourth (20.3%) of them manifested both symptoms.
3. The rate of farmers with allergic symptoms was higher in younger generations and many of these symptoms occurred within these five years.
4. The rate of positive skin reactions of each allergen extracts were 40.5% for Japanese pear pollens, 63.8% for apple pollens, 30.5% for cedar pollens, 6.7% for orchard grass pollens and 10.5% for house dust.
From a pollen calender of Nagano Prefecture, high rate of allergic symptons during the bloom of pear and apple and the results of the intradermal skin reaction tests, it may, be suggested that a considerable number of farmers possibly suffer from pear and apple pollinosis. The rates showed above are much higher than reported so far.