Does change of residence affect pollinosis? A study of Japanese university students.

The effects of change of residence on pollinosis symptoms remain unclear. We investigated the effects of geographical change of residence on pollinosis symptoms among university freshmen. All freshmen (n = 2142) entering Shinshu University in 2011 completed self-administered questionnaires. Associations between history of pollinosis and environmental factors were assessed. Subjects were classified into three groups according to pollen count at previous residences (stationary, low pollen, and high pollen). Pollinosis both before and after relocation were compared among and within the groups. Of the 1558 subjects, 540 (34.7%) developed pollinosis before and 483 (31.0%) after entering university. The rates of pre- and post-university entrance pollinosis were 40.0 and 32.5% in the high pollen group (P < 0.001) but were similar in the other two groups. Pollinosis symptoms decreased among students that moved from high to low pollen areas, indicating that pollinosis was affected by geographic environmental factors.