BirthmarksPigmented Birthmarks (usually brown) are caused by clusters of pigment cells. Pigmented birthmarks are tan or brown-colored skin marks.

Some of the most common types of pigmented birthmarks are:

  • Café-au-lait Spots: Café-au-lait spots are coffee-colored skin patches. Many children have one or two, but if more than six have developed by the time the child is five, they should be checked by a doctor.
  • Mongolian Spots: Mongolian spots are blue-grey or bruised-looking birthmarks that are present from birth. They’re more commonly seen in darker-skinned people and usually occur over the lower back or buttocks. However, they can also appear elsewhere on the body or limbs. Mongolian spots may last for months or years, but they usually disappear by the time a child reaches four years of age. They’re completely harmless and don’t need treatment. They may sometimes be mistaken for a bruise.
  • Congenital Melanocytic Naevi: Congenital melanocytic naevi are also known as congenital moles. They’re relatively large brown or black moles that are present from birth. They’re fairly common and are caused by an overgrowth of pigment cells in the skin. Most congenital melanocytic naevi become proportionally smaller and less obvious with time, although they may darken during puberty or become bumpy or hairy. The risk of a naevi developing into skin cancer is low, but the risk increases the larger it is.

Most birthmarks are harmless and don’t require any treatment. In some cases, a birthmark will need to be treated for medical reasons – for example, if a haemangioma blocks the airways, affects vision or becomes ulcerated. Some people may also decide to seek treatment for cosmetic reasons. To learn more about birthmarks or to schedule an appointment with Dr. Holy to have a birthmark evaluated, contact The Center for Advanced Dermatology at 602-867-7546 or