According to the Mexican Social Security Institute nationwide, around half of Mexican babies have the slate grey nevus.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.Highland Peruvians have the slate grey nevus. Treatment
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 terminology
The slate grey nevus is referred to in the Japanese idiom shiri ga aoi (尻が青い), meaning "to have a blue butt", which is a reference to immaturity or inexperience. In Mongolian language, it is known as "Хөх толбо". Korean mythology explains the nevus as a bruise formed when Samshin halmi or Samsin Halmoni (Korean: 삼신할머니), a shaman spirit to whom people pray around childbirth, slapped the babys behind to hasten the baby to quickly get out from the mothers womb. "Mongolian Mark", the middle third of the 2004–5 novel The Vegetarian, is named after the title characters nevus, which obsesses her brother-in-law. 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 babys backside, telling it to be born.
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, Bälzs 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 Yupik 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.