INTRODUCTION

  The number of hay fever patients is expected to increase in the future.There is a disease called allergy rhinitis (hay fever) caused by pollen of plants in Japan. There are various kinds of plants causing pollinosis, among those pollinosis, the patients with Japanese cedar hay fever, has increased by 10% since 1998.

And for now, 1 in 5 people (more than 20 million people), have hay fever.

The number of hay fever patients is expected to increase in the future.

  Besides cedar pollen, there are still plants that cause pollinosis in Japan. The major pollinosis-causing plants in Japan, as shown in figure below, are cedar, hinoki, ambrosia, poaceae, birch.

The most common cedar pollinosis patients, occupied about 70% of patients with hay fever disease. Besides that, as Japan has four distinct seasons, and because flowers blooms differently by season, the time for the pollen scattered by pollen-causing plants are different.

Cedar’s pollen scatters from winter to spring, hinoki and birch in spring, poaceae from spring to autumn and ambrosia in the autumn. Since pollinosis occurs specifically, there is also the possibility that one have multiple types of pollinosis causes by plants. Therefore, in some cases, some people suffers from hay fever throughout the year.

  In japan, hay fever is a big issue as one in five japanese suffers from hay fever. Symptoms of hay fever is individually different, but basically, runny or blocked nose, frequent sneezing and coughing, itchy and red or watery eyes, loss of smell and so on.