Hidradenitis Suppurativa Support Group
Hidradenitis suppurativa (hi-drad-uh-NIE-tis sup-yoo-ruh-TIE-vuh) is rare, long-term skin condition that features small, painful lumps under the skin. The disease manifests as clusters of chronic abscesses or boils, sometimes as large as baseballs, that are extremely painful to the touch and may persist for years with occasional to frequent periods of inflammation,...

http://www.zeemaps.com/241892
To me, it visually illustrates the often overlooked cultural, dietary and environmental factors in areas with higher concentrations as well as those areas with few pinpoints. Comparing/Contrasting regional areas gets complicated given the lack of knowledge, the different global/medical labels for HS and the lack of modern infrastructure in less developed countries etc but there sure seems to me to be correlations or patterns to individuals with HS beyond our basic heredity or genetic links.