The scratch test positive rate and the prevalence of nasal allergy in students from Nanjing Medical University, China

III. Nasal Allergy against orchardgrass and ragweed

Abstract

An epidemiological study on nasal allergy was conducted on freshman and senior students at Nanjing Medical University, China. In this study, we examined the presence of nasal allergy against orchardgrass and ragweed, in addition to the other common allergens (house dust, mites snd cedar pollen) examined in previous reports. No case of nasal allergy against orchardgrass or ragweed was found, and only one case, who was positive against mites, was diagnosed to have a nasal allergy. In Japan, only a small number of nasal allergy cases were observed before the seventies, however, the number has dramatically increased since then. It is thus speculated that changes in external factors somehow contribute to this increase. Although we cannot make any sweeping statements about China, which has a vast land area, and where variations among different localities are quite large, the present social development status seems to be closely similar to that in Japan before the seventies. Therefore, if China continues to achieve economic affluency similar to that achieved by Japan in the seventies, then nasal allergies might also increase in China the way they have in Japan.