Geographic distribution of the 49 cases of Japanese summer type hypersensitivity pneumonitis (SHP). The disease is more common in the western and southern parts of the country and has a predilection for areas bordering the Pacific Ocean area when compared with areas facing the Sea of Japan. The northernmost site of the disease was in the Saitama Prefecture, located at a latitude of 36° north. ● indicates one SHP event. (blue human-shaped symbol) and (red human-shaped symbol) indicate male or female adult patients, respectively. (small blue human-shaped symbol) and (small red human- shaped symbol) indicate boy or girl patients who lived with their family. The map of Japan was obtained from the site (http://aoki2.si.gunma-u.ac.jp/map/map.html).