Mongolian spots
refer to a common type of benign infant birthmark that appears blue or blue-gray and usually ranges in size from 2 to 8 cm, although connected markings may appear larger. Mongolian spots typically develop on the shoulders, back or buttocks and become visible at birth or shortly after. This condition is sometimes referred to as congenital dermal melanocytosis or dermal melanocytosis.
Cause
Mongolian spots are caused by aggregations of melanocytes, melanin-rich cells, in the skin. Melanin is a skin pigment that gives the birthmark its bluish-gray hue. Doctors believe that Mongolian spots may develop in a fetus when melanocytes become trapped as they move from the neural crest to the outer layer of skin.
Identification
Healthcare professionals can usually identify Mongolian spots by visually examining the baby. Doctors do not use tests to identify Mongolian spots. However, Mongolian spots are sometimes mistaken for bruises, which may be a sign of child abuse. Mongolian spots differ from bruises in that they are not tender and they do not fade or change color.
Risk Factors
Darker-skinned infants are more likely than lighter-skinned infants to develop Mongolian spots. They occur most frequently in infants of African, Asian, American Indian and East Indian descent. According to "Pediatric Dermatology," 91 percent of Asian infants, 80 percent of African-American infants, 46 percent of Hispanic infants and only 10 percent of white infants develop Mongolian spots.
Outlook
Mongolian spots are not a sign of disease and do not require treatment. The birthmarks are not related to skin cancer or other conditions. Mongolian spots usually fade within a few years of birth and almost always disappear completely by the time the child reaches adolescence. Only 3 to 4 percent of infants with Mongolian spots still have them by age 5, according to "Pediatric Dermatology."
