Mongolian spot
Encyclopedia
A Mongolian spot, also known as "Mongolian blue spot," "Congenital dermal melanocytosis," and "Dermal melanocytosis" is a benign
, flat, congenital
birthmark
with wavy borders and irregular shape, discovered on and named after Mongolians by Erwin Bälz
. It is also extremely prevalent among East Asians, Polynesians
, Native Americans
, and East Africa
ns. 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 even deep brown.
developmental condition exclusively involving the skin
. The blue colour is caused by melanocyte
s, melanin
-containing cells, that are usually located in the epidermis but are in the deeper region of the skin known as the dermis in the location of the spot. Usually, as multiple spots or one large patch, it covers one or more of the lumbosacral area (lower back
), the buttocks, flank
s, and shoulder
s. 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 embryo
nic development.
The condition is unrelated to gender; male and female infants are equally predisposed to Mongolian spot. The spots are harmless.
Among those who are not aware of the background of the Mongolian spots, it may sometimes be mistaken for a bruise, possibly resulting in unfounded concerns about abuse.
infants, respectively. Approximately 90% of Polynesians and Micronesians are born with Mongolian spots, as are about 46% of Latin American children (those who have some sort of Native American ancestry). These spots also appear on 1-10% of babies of full Caucasian descent.
idiom shiri ga aoi (尻が青い), meaning "to have a blue butt."
Benign
A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
, flat, congenital
Congenital disorder
A congenital disorder, or congenital disease, is a condition existing at birth and often before birth, or that develops during the first month of life , regardless of causation...
birthmark
Birthmark
A birthmark is a benign irregularity on the skin which is present at birth or appears shortly after birth, usually in the first month. They can occur anywhere on the skin. Birthmarks are caused by overgrowth of blood vessels, melanocytes, smooth muscle, fat, fibroblasts, or...
with wavy borders and irregular shape, discovered on and named after Mongolians by Erwin Bälz
Erwin Bälz
Erwin Bälz was a German internist, anthropologist, personal physician to the Japanese Imperial Family and cofounder of modern medicine in Japan.- Biography :...
. It is also extremely prevalent among East Asians, Polynesians
Polynesians
The Polynesian peoples is a grouping of various ethnic groups that speak Polynesian languages, a branch of the Oceanic languages within the Austronesian languages, and inhabit Polynesia. They number approximately 1,500,000 people...
, Native Americans
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
, and East Africa
East Africa
East Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...
ns. It normally disappears three to five years after birth and almost always by puberty
Puberty
Puberty is the process of physical changes by which a child's body matures into an adult body capable of reproduction, as initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy...
. The most common color is blue, although they can be blue-gray, blue-black or even deep brown.
Origin
The Mongolian spot is a congenitalCongenital disorder
A congenital disorder, or congenital disease, is a condition existing at birth and often before birth, or that develops during the first month of life , regardless of causation...
developmental condition exclusively involving the skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
. The blue colour is caused by melanocyte
Melanocyte
-External links: - "Eye: fovea, RPE" - "Integument: pigmented skin"...
s, melanin
Melanin
Melanin is a pigment that is ubiquitous in nature, being found in most organisms . In animals melanin pigments are derivatives of the amino acid tyrosine. The most common form of biological melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids, and their reduced forms...
-containing cells, that are usually located in the epidermis but are in the deeper region of the skin known as the dermis in the location of the spot. Usually, as multiple spots or one large patch, it covers one or more of the lumbosacral area (lower back
Human back
The human back is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck and the shoulders. It is the surface opposite to the chest, its height being defined by the vertebral column and its breadth being supported by the ribcage and shoulders...
), the buttocks, flank
Flank
Flank may refer to:* Flank, the side of either a horse or a military unit*Flanking maneuver in military tactics* Flank , the waveform edge formed when a signal goes high or low...
s, and shoulder
Shoulder
The human shoulder is made up of three bones: the clavicle , the scapula , and the humerus as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The major joint of the shoulder is the glenohumeral joint, which...
s. It results from the entrapment of melanocytes in the lower half to two-thirds of the dermis
Dermis
The dermis is a layer of skin between the epidermis and subcutaneous tissues, and is composed of two layers, the papillary and reticular dermis...
during their migration from the neural crest
Neural crest
Neural crest cells are a transient, multipotent, migratory cell population unique to vertebrates that gives rise to a diverse cell lineage including melanocytes, craniofacial cartilage and bone, smooth muscle, peripheral and enteric neurons and glia....
to the epidermis during embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
nic development.
The condition is unrelated to gender; male and female infants are equally predisposed to Mongolian spot. The spots are harmless.
Among those who are not aware of the background of the Mongolian spots, it may sometimes be mistaken for a bruise, possibly resulting in unfounded concerns about abuse.
Prevalence
Rough estimates are that the Mongolian spots are most prevalent among infants of East Asian groups. Infants may be born with one or more Mongolian spots ranging from small area on the buttocks to a larger area on the back. They also occur in about 90-95% and about 80-85% of East African and Native AmericanIndigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
infants, respectively. Approximately 90% of Polynesians and Micronesians are born with Mongolian spots, as are about 46% of Latin American children (those who have some sort of Native American ancestry). These spots also appear on 1-10% of babies of full Caucasian descent.
Cultural references
The Mongolian spot is referred to in the JapaneseJapanese language
is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...
idiom shiri ga aoi (尻が青い), meaning "to have a blue butt."