In 1953 Dr Saxtorph, medical advisor to the Greenland department (part of the Danish government), wrote that the Greenlanders do not like outsiders to see or discuss these birthmarks; "they doubtless feel as a reminiscence of the time when they lived on a low cultural level".The presence or absence of the slate grey nevus was used by racial theorists such as Joseph Deniker (1852-1918), the French anthropologist.The Journal of Cutaneous Diseases Including Syphilis, Volume 23 contained several accounts of the slate grey nevus on children in the Americas:

Holm ("Ethnological Sketch. Communications on Greenland," X., Copenhagen, 1887) announced the presence of the spot in the east part of Greenland. Bartels ("The So-Called Mongolian Spots on Infants of Esquimaux," Ethnologic Review, 1903) received letters regarding it from East Greenland and also from Esquimaux of Alaska. In half-breed European-Esquimaux, Hansen says he has encountered it. Among Indians of North Vancouver, British Columbia, there are observations made by Baelz as well as by Tenkate (secondhand). In the Mayas of Central America, Starrs (Data on the Ethnography of Western Mexico, Part H., 1902) facts are corroborated by Herman (Aparecimiento de la Mancha Mongolica. Revista de Ethnologia, 1904). He cites A. F. Chamberlain (Pigmentary Spots, American Anthropologist, 1902,) and Starr (Sacral Spots of Mayan Indians, Science, New Series, xvii., 1903). In Central America, according to these authorities, the spot is called Uits, "pan," and it is an insult to speak of it. It disappears in the tenth month. It is bluish-reddish (in these Native people), and is remarkable by its small size.
Collagen disease is a term previously used to describe systemic autoimmune diseases (e.g., rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis), but now is thought to be more appropriate for diseases associated with defects in collagen, which is a component of the connective tissue.The term "collagen disease" was coined by Dr. Alvin F. Coburn in 1932, on his quest to discover streptococcal infection as the cause for rheumatic fever. See also
Collagenopathy, types II and XI
Connective tissue disease

References
External links
Collagen disease entry in the public domain NCI Dictionary of Cancer Terms
 This article incorporates public domain material from the U.S. National Cancer Institute document: "Dictionary of Cancer Terms".