eMedicine - Mongolian Spot : Article by Zeina Tannous, MD

eMedicine - Mongolian Spot : Article by Zeina Tannous, MD: "Background: Mongolian spot refers to a macular blue-gray pigmentation usually on the sacral area of normal infants. It is usually present at birth or appears within the first weeks of life. It typically disappears spontaneously within 4 years but can persist for life.

Pathophysiology: The Mongolian spot is a congenital, developmental condition exclusively involving the skin. It results from entrapment of melanocytes in the dermis during their migration from the neural crest into the epidermis.
Frequency:

Internationally: The prevalence of Mongolian spots varies among different ethnic groups. This condition is most common among Asians. It also has been reported in 80% of East African children, in 46% of Hispanic children, and in 1-9% of white children.

Mortality/Morbidity: Mongolian spot is not associated with mortality or morbidity.

Race: Mongolian spots are observed in more than 90% of infants of the Mongoloid race (ie, East Asians, Indonesians, Polynesians, Micronesians, Amerindians, Eskimos).
Sex: No sex predilection is reported.

Age: Mongolian spot is usually present at birth, but it can also appear within the first weeks of the neonatal period. "