Mongolian Spots and Hyperpigmentation

Large, blue-black, macular areas over the buttocks and presacral regions were present at birth in this black child. Significant hyperpigmentation of the genitals also was evident. Scrotal hyperpigmentation is not an uncommon finding in a black newborn. However, the intensity of the penile hyperpigmentation in this baby is unusual.

Mongolian spots, which most commonly occur over the buttocks and presacral regions, are caused by melanocytes located deep in the epidermis that have failed to migrate from the neurocrest to the superficial epidermis. These hyperpigmented areas occur in more than 90% of African Americans and Native Americans, 81% of Asian and 70% of Hispanic newborns, and 9.6% of white infants.

Mongolian spots often fade during the first 1 to 2 years of life and generally disappear by ages 7 to 13. A few may persist into adulthood. The lesions are benign. Reassurance that the pigmentation will fade with time is the only treatment necessary.