Slate grey nevus (congenital dermal melanocytosis, Mongolian spot) is a benign, flat, congenital birthmark, with wavy borders and an irregular shape. In 1883, it was described and named after Mongolians by Erwin Bälz, a German anthropologist based in Japan, who erroneously believed it to be most prevalent among his Mongolian patients.[2][3][4][5] It normally disappears three to five years after birth and almost always by puberty. The most common color is blue, although they can be blue-gray, blue-black or deep brown.

Slate grey nevus
Other namesMongolian spot, Mongolian blue spot, congenital dermal melanocytosis,[1] dermal melanocytosis[1]
Girl with slate grey nevus


Slate grey nevus is a congenital developmental condition—that is, one existing from birth—exclusively involving the skin. The blue colour is caused by melanocytes, melanin-containing cells, that are usually located in the surface of the skin (the epidermis), but are in the deeper region (the dermis) in the location of the spot.[6] Usually, as multiple spots or one large patch, it covers one or more of the lumbosacral area (lower back), the buttocks, sides, and shoulders.[6] It results from the entrapment of melanocytes in the lower half to two-thirds of the dermis during their migration from the neural crest to the epidermis during embryonic development.[6]

Male and female infants are equally predisposed to slate grey nevus.[citation needed]

People who are not aware of the background of the slate grey nevus may mistake them for bruises, possibly resulting in mistaken concerns about abuse.[7][8][9]

Anthropological descriptionEdit

The French anthropologist Robert Gessain interested himself in what he called the tache pigmentaire congenitale or coloured birthmark, publishing multiple papers in the Journal de la Société des Américanistes, an academic journal covering the cultural anthropology of the Americas. Gessain spent time with the Huehuetla Tepehua people in Hidalgo, Mexico, and wrote in 1947 about the spot's "location, shape, colour, histology, chemistry, genetic transmission, and racial distribution". He had previously spent several winters in Greenland, and wrote an overview in 1953 of what was known about the spot. He hypothesised that the age at which it faded in various populations might prove to be a distinguishing characteristic of those groups. Gessain claimed that the spot was first observed amongst the Inuit.[10]

Hans Egede Saabye, a Danish priest and botanist, spent 1770-1778 in Greenland. His diaries, published in 1816 and translated into several European languages, contained much ethnographic information. He described the spot on newborns, saying he had seen it often when the infants were presented naked for baptism. A second Danish observer was doctor and zoologist Daniel Frederik Eschricht, mainly based in Copenhagen. In 1849 he wrote of the "mixed" babies he had delivered at the lying-in hospital. He also says that "the observation made for the first time by Saabye about Inuit children has been completely confirmed by Captain Holbøll", who sent him a fetus pickled in alcohol.[10]

Gessain goes on to state that it was only in 1883 that an anthropologist mentions the spot. It was Erwin Bälz, a German working in Tokyo, who described a dark blue mark on Japanese infants. He presented his findings in 1901 in Berlin, and from that point on, Bälz's name was associated with certain skin cells containing pigment. Captain Gustav Frederik Holm wrote in 1887 that his Greenlandic interpreter Johannes Hansen (known as Hanserak) attested to the existence of the birthmark over the kidney region of newborns, which grows larger as they grow older. That year, the Danish anthropologist Soren Hansen drew the connection between the observations of Bälz in Japan and Saabye in Greenland. "This cannot be a coincidence. It is not the first time that the resemblance between the Japanese and the Eskimo has been pointed out." Fridtjof Nansen, the Norwegian polar explorer, said that the spot was widespread in the mixed Danish-Inuit population of West Greenland. Soren Hansen confirmed this. A missionary in Bethel, Alaska, a traditional gathering place of Yup'ik people, reported that the spots were common on children. Rudolf Trebitsch, an Austrian linguist and ethnologist, spent the summer of 1906 on the West Coast of Greenland, and listed all the examples he came across. Gessain went to north Labrador in 1926, looking for children with these spots. 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".[10]

The presence or absence of the slate grey nevus was used by racial theorists such as Joseph Deniker (1852-1918), the French anthropologist.[11]

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, Starr's (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. The mulberry colored spot is very well known in Afro-Brazilians. In Brazil, among individuals of mixed Indigenous American and West African descent (pardo) it is called "genipapo", from its resemblance in color (bluish-gray) to an indigenous fruit of Brazil, named genipapo (a Native word adopted into Portuguese).


Infants may be born with one or more slate grey nevus ranging from small area on the buttocks to a larger area on the back. The birthmark is prevalent among East, South, Southeast, North and Central Asian peoples, Indigenous Oceanians (chiefly Micronesians and Polynesians), certain populations in Africa,[12] Amerindians,[13] non-European Latin Americans, Caribbeans of mixed-race descent, and Turkish people.[6][14][15][16]

They occur in around 80%[17] of Asians, and 80%[17] to 85% of Native American infants.[15] Approximately 90% of Polynesians and Micronesians are born with slate grey nevus, as are about 46% of children in Latin America,[18] where they are associated with non-European descent. These spots also appear on 5–10% of babies of full Caucasian descent; Coria del Río in Spain has a high incidence due to the presence of descendants of members of the delegation led by Hasekura Tsunenaga, the first Japanese official envoy to Spain in the early 17th century.[15][19][better source needed] African American babies have slate grey nevus at a frequencies of 90%[17] to 96%.[20]

The prevalence of the spot in mixed race populations is not completely known. Some dermatologists have reported that the spot is not at all present in mestizo populations.[21] According to other accounts, almost all of the mestizo (mixed Spanish-Indian) population of Mexico has the spot.[22] A study performed in hospitals of Mexico City reported that, on average, 51.8% of Mexican newborns presented slate grey nevus, while it was absent on 48.2% of the analyzed babies.[23] According to the Mexican Social Security Institute (shortened as IMSS) nationwide, around half of Mexican babies have the slate grey nevus.[24] The rate of this spot among mixed race children is most likely somewhere around 1 in every 2 babies, with a slight bias against it being inherited.[25][26]

Central American indigenous children were subjected to racism due to their slate grey nevus but progressive circles began to make having the slate grey nevus popular after the late 1960s.[27]

Highland Peruvians have the slate grey nevus.[28]


As a congenital benign nevus, Mongolian spots do not require treatment and in most cases disappear before adolescence. No cases of malignant degeneration have been reported.

Cultural terminologyEdit

The slate grey nevus is referred to in the Japanese idiom shiri ga aoi (尻が青い), meaning "to have a blue butt",[29][30] which is a reference to immaturity or inexperience.

Korean mythology explains the nevus as a bruise formed when Samshin halmi (Korean: 삼신할미), a shaman spirit to whom people pray around childbirth, slapped the baby's behind to hasten the baby to quickly get out from his or her mother's womb.

In Chinese, it is referred to as "青痕" (Pinyin: Qīng Hén; Literally: Blue Mark). Among common folk it is said to be caused by the Buddhist goddess of childbirth Songzi Guanyin (Simplified Chinese: 送子观音; Pinyin: Sòng Zǐ Guān Yīn; Literally: The Goddess of Baby Sending) when she is slapping the babies backside telling it to be born. Others say it's because the baby does not want to leave the mother's womb so Songzi Guanyin will kick it out, leaving the bruise. While a small portion of people, wrongfully, believe it happens when the doctor is slapping the baby's backside to make it cry. Scientifically, it is also referred to as "蒙古斑" (Pinyin: Měng Gǔ Bān; Literally: Mongolian Spot)

In Khmer, it is known as "khnau" (ខ្នៅ) which translates to 'Mongolian spot' as well as other skin conditions such as vitiligo and leucoderma.[31]

The mark is also common among Maya people of the Yucatan Peninsula [32] where is referred to as Wa in Maya, which means "circle".

In Ecuador, the native Indians of Colta are insultingly referred to in Spanish by a number of terms which allude to the slate grey nevus.[33]

In Spanish it is called mancha mongólica and mancha de Baelz (see Erwin Bälz).[34]

See alsoEdit


  1. ^ a b Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. p. 1720. ISBN 978-1-4160-2999-1.
  2. ^ Die koerperlichen Eigenschaften der Japaner.(1885) Baelz.E. Mittheil.d.deusch Gesell.f.Natur-u-Voelkerheilkunde Ostasiens. Bd.4.H.32
  3. ^ Circumscribed dermal melanosis (Mongolian spot)(1981) Kikuchi I, Inoue S. in "Biology and Diseases of Dermal Pigmentation", University of Tokyo Press, p83
  4. ^ Bernard Cohen (1993). Atlas of pediatric dermatology. Wolfe. pp. 6–17. ISBN 978-1563750199. Retrieved May 17, 2014.
  5. ^ JAMA: The Journal of the American Medical Association, Volume 51. American Medical Association. American Medical Association. 1908. p. 2262. Retrieved May 17, 2014.CS1 maint: others (link)
  6. ^ a b c d Mongolian blue spots – Health care guide discussing the Mongolian blue spot.
  7. ^ Mongolian Spot - English information of Mongolian spot, written by Hironao NUMABE, M.D., Tokyo Medical University.
  8. ^ Empson, Rebecca M. (2010). Harnessing fortune : personhood, memory and place in northeast Mongolia. Oxford: Oxford University Press. ISBN 9780197264737.
  9. ^ Robert M. Reece; Stephen Ludwig, eds. (2001). Child Abuse: Medical Diagnosis and Management (2, illustrated ed.). Lippincott Williams & Wilkins. p. 180. ISBN 978-0781724449. Retrieved May 17, 2014.
  10. ^ a b c Gessain, Robert (1953). "La tache pigmentaire congénitale chez les Eskimo d'Angmassalik" (PDF). Journal de la Société des Américanistes. 42: 301–332. doi:10.3406/jsa.1953.2408.
  11. ^ Deniker, Joseph (4 April 1901). "Les taches congénitales dans la région sacro-lombaire considérées comme caractère de race". Bulletins et Mémoires de la Société d'Anthropologie de Paris. 2 (2): 274–281. doi:10.3406/bmsap.1901.5961.
  12. ^ Kevin C. Stuart (1997). Mongols in Western/American consciousness (illustrated ed.). Edwin Mellen Press. p. 95. ISBN 978-0773484436. Retrieved May 17, 2014.
  13. ^ Miller (1999). Nursing Care of Older Adults: Theory and Practice (3, illustrated ed.). Lippincott Williams & Wilkins. p. 90. ISBN 978-0781720762. Retrieved May 17, 2014.
  14. ^ Egemen A, Ikizoğlu T, Ergör S, Mete Asar G, Yilmaz O (July 2006). "Frequency and characteristics of Mongolian spots among Turkish children in Aegean region". Turk J Pediatr. 48 (3): 232–6. PMID 17172067.
  15. ^ a b c "About Mongolian Spot". Retrieved 1 October 2015.
  16. ^ Transcultural Medicine: Dealing with patients from different cultures
  17. ^ a b c Giger, Joyce Newman (2016). Transcultural Nursing – E-Book: Assessment and Intervention. Elsevier Health Sciences. p. 176. ISBN 978-0323400046. Retrieved 14 September 2017.
  18. ^ Epidemiology of Mongolian spot on MedScape
  19. ^ "Spain's Japon clan has reunion to trace its 17th century roots". The Japan Times. Retrieved 1 October 2015.
  20. ^ N Silverberg (2012). Atlas of Pediatric Cutaneous Biodiversity: Comparative Dermatologic Atlas of Pediatric Skin of All Colors. Springer Science & Business Media. p. 34. ISBN 978-1461435648. Archived from the original on 2012. Retrieved May 17, 2014.
  21. ^ Douglass W. Montgomery (1905). Journal of Cutaneous Diseases Including Syphilis Volume 23. 23. American Dermatological Association. p. 210. Retrieved October 27, 2019.
  22. ^ Lawrence C. Parish; Larry E. Millikan, eds. (2012). Global Dermatology: Diagnosis and Management According to Geography, Climate, and Culture. M. Amer, R.A.C. Graham-Brown, S.N. Klaus, J.L. Pace. Springer Science & Business Media. p. 197. ISBN 978-1461226147. Retrieved May 17, 2014.
  23. ^ “Alteraciones cutáneas del neonato en dos grupos de población de México”, Scielo, March/April 2005. Retrieved on 18 May 2017.
  24. ^ “Tienen manchas mongólicas 50% de bebés”, El Universal, January 2012. Retrieved on 3 July 2017.
  25. ^ Lewis B. Holmes (2011). Common Malformations. Oxford University Press. p. 414. Retrieved October 27, 2019.
  26. ^ Elpidio Tomas Ayala (1971). THE SACRAL OR MONGOLIAN SPOT: MORPHOLOGY AND EXPRESSION. Wayne State University Press. p. 562. Retrieved October 27, 2019.
  27. ^ Arturo Arias (2007). Taking Their Word: Literature and the Signs of Central America. U of Minnesota Press. p. 239. ISBN 978-1452913162. Archived from the original on 2007. Retrieved May 17, 2014.
  28. ^ Herbert Goldhamer (2015). The Foreign Powers in Latin America. Princeton Legacy Library, Rand Corporation research study. Princeton University Press. p. 105. ISBN 978-1400869152. Archived from the original on 2015. Retrieved May 17, 2014.
  29. ^ (in Japanese)
  30. ^ "The butt is blue": the untold story, Language Log, October 15, 2008 @ 3:14 pm; comment of October 16, 2008 @ 11:39 am
  31. ^ Headley, Robert K. (1997). "Cambodian-English Dictionary". SEAlang Library. Archived from the original on 2007. Retrieved July 21, 2019.
  32. ^ Life Magazine - Ancient and Modern Maya (June 1947)
  33. ^ Eileen Maynard (1966). The Indians of Colta: Essays on the Colta Lake Zone, Chimborazo (Ecuador). Department of Anthropology, Cornell University. p. 6. Archived from the original on May 30, 2008. Retrieved May 17, 2014.
  34. ^ Vox (2012). Vox Super-Mini Medical Spanish and English Dictionary. Vox dictionaries. McGraw Hill Professional. pp. 184, 121. ISBN 978-0071788632. Retrieved May 17, 2014.

External linksEdit

External resources