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Mongolian blue spots

  • Mongolian blue spots are a type of birthmark. They are flat blue or blue/grey spots with an irregular shape that commonly appear at birth or soon after.

    Although they may look like bruises, it is important to recognise that Mongolian blue spots are birthmarks, not bruises.

    Mongolian blue spots are most common at the base of the spine, on the buttocks, back and shoulders.  They are extremely common among Asian children, as well as children with dark skin, including people of Indian and African descent.

    Mongolian blue spots may also be called congenital dermal melanocytosis or dermal melanocytosis. 

    Signs and symptoms of Mongolian blue spots

    • Mongolian blue spots are bluish to blue-grey spots, which may resemble bruising.
    • The coloured area feels the same as normal skin to the touch.
    • They are most commonly found at the base of the spine, on the buttocks and back, and may cover a large area of the back.
    • Occasionally the spots can appear elsewhere on the body, like the shoulder.

    If your child has Mongolian blue spots, they are otherwise healthy. The birthmarks are not associated with any other medical symptoms or illnesses, and do not cause any pain.

    Treatment for Mongolian blue spots

    No treatment is needed or recommended. The spots do not cause any medical complications. The discolouration often fades completely within 2 years, and the birthmarks have usually gone once the child reaches adolescence. Less than 3 per cent will continue into adulthood, and these are usually ones found outside of the buttock and spine areas.

    When to see a doctor

    Most Mongolian blue spots do not need to be seen by a doctor, unless there is some doubt as to the type of mark your child has. If the blue spots are particularly large, growing or located near the mouth, then these should be reviewed by a paediatrician or paediatric dermatologist (skin specialist).

    Key points to remember

    • Mongolian blue spots are a type of birthmark, with flat blue or blue/grey spots.
    • They may resemble bruises but they are not bruises, they are birthmarks.
    • There are no medical complications associated with Mongolian blue spots.
    • No treatment is needed – they will usually go away by the time the child reaches adolescence.

    For more information

    • See your family doctor, paediatrician or dermatologist.

    Common questions our doctors are asked

    How can I tell if it's a bruise or a Mongolian blue spot?

    Mongolian blue spots and bruises do look very similar, and the birthmarks are often mistaken for bruises. However, they are different in a few ways. Bruises change colour, size and shape over the course of just a few days, while Mongolian blue spots stay the same for many years. Also, Mongolian blue spots are not painful when touched. Mongolian blue spots are present from birth.

    What can I do if my child's Mongolian blue spot is very prominent and is causing them embarrassment? Is laser treatment an option?

    We do not recommend any treatment for Mongolian blue spots, as it is unnecessary because the birthmarks will fade over time on their own. Treatment, such as laser therapy, may cause side effects, including infection and scarring.

    Developed by The Royal Children's Hospital Dermatology department. We acknowledge the input of RCH consumers and carers.

    Reviewed June 2018.

    Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit


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