Satoshi Hamada1, Eriko Ogino2, Hirotaka Yasuba3. 1. Department of Respiratory Medicine, Hikone Municipal Hospital, Hikone, Japan. 2. Kyoto Station-front Ear Nose and Allergy Clinic, Kyoto, Japan. 3. Department of Airway Medicine, Mitsubishi Kyoto Hospital, Kyoto, Japan; Department of Respiratory Medicine, Tango Central Hospital, Kyotango, Japan. Electronic address: hyacchan@ga2.so-net.ne.jp.