Mongolian Spot

Key Points
Common type of birthmark
Caused when pigment cells fail to arrive at their destination and end up in the lower skin layers
Consists of grey-blue areas of pigmentation, typically on the lower back or buttocks, and are of varying size

Mongolian spots are a common type of birthmark. The condition is congenital, and consists of grey-blue areas of pigmentation, typically found on the lower back or buttocks, though in some cases pigmented areas may appear on the face or limbs. There are no other associated symptoms.

Mongolian spots are caused when pigment cells fail to arrive at their destination during fetal development and end up in the lower layers of skin. The condition appears in over 90% of births of Mongoloid descent, and less frequently in other ethnic groups.

Differential Diagnosis (Other conditions with similar appearance)
Blue Nevi
Nevi of Ota and Ito
Bruising

Diagnosis
Key Points
Diagnosis based on appearance of the affected area
Other testing is not generally required

Diagnosis of Mongolian spots is based on the appearance of the affected area. Other testing is not generally required.

Treatment
Treatment is not required as lesions are benign
*In most cases, lesions will resolve during early childhood

Mongolian spots do not typically require treatment, as lesions are benign. In the majority of cases, lesions will resolve spontaneously during early childhood, usually by age 4. In some persons, larger lesions may be persistent over a period of years.