Allergies are a common health concern in Japan, with hay fever or pollinosis being the most common allergy. Other common allergens include dust mites, mold, animal dander, and seafood. To avoid allergies, it is recommended to keep living spaces clean and dry, wear a mask during peak pollen hours, use an air purifier with a HEPA filter, read food labels carefully and ask about ingredients before ordering food if you have a severe allergy.