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Mongolian blue spots


Mongolian spots are flat, blue, or blue-gray skin markings near the buttocks that appear at birth or shortly thereafter.

Alternative Names

Mongolian spots; Congenital dermal melanocytosis; Dermal melanocytosis


Mongolian blue spots are common among persons who are of Asian, East Indian, and African descent.


Mongolian spots are not cancerous and are not associated with disease. The markings may cover a large area of the back.

Mongolian blue spots are sometimes mistaken for bruises. This can raise a question about possible child abuse. It is important to recognize that Mongolian blue spots are birthmarks, not bruises.

The marking are usually:

  • Blue or blue-gray spots on the back, buttocks, base of spine, shoulders, or other body areas
  • Flat with irregular shape and unclear edges
  • Normal in skin texture
  • 2 to 8 centimeters wide

Exams and Tests

No tests are needed. The health care provider can diagnose this condition by looking at the skin.


No treatment is necessary or recommended.

Outlook (Prognosis)

The spots often fade in a few years and are almost always gone by adolescence.

When to Contact a Medical Professional

All birthmarks should be examined by a health care provider during the routine newborn examination.



James WD, Berger TG, Elston DM, eds. Andrews' Diseases of the Skin: Clinical Dermatology. 11th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 28.

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