Pigmented skin markings range from brown or black to bluish, or blue-gray in color. There is no known way to prevent these types of birthmarks. A dermatologist should examine the birthmark to determine if it is of concern or requires treatment.
Mongolian Spots: These appear as bluish, bruise-like marks and most often appear on the buttocks and lower back, but can be seen anywhere on the body. Most commonly seen in darker skin types, especially Asians.
Congenital Nevi (Moles): These can be seen at birth and range in size from a few millimeters to extensive, bathing trunk-sized lesions. Only very large congenital moles (>20 cm diameter) have a higher risk of developing into melanoma, but the smaller lesions do not.
Café-au-Lait Spots: These are light tan or light brown spots that are usually oval in shape and may develop at birth.
In most cases, no treatment is needed. When removal is desired for cosmetic reasons or because of suspicious changes, surgical excision may be an option for congenital nevi. Café-au-lait spots can also be treated with laser therapy.