Mongolian blue spots, also known as congenital dermal melanocytosis, lumbosacral dermal melanocytosis, slate gray nevus, or dermal melanocytosis, are a type of birthmark that is flat and blue or blue-gray in appearance. It usually appears at the base of the spine, buttocks, upper back, or shoulders. Some babies may have it at birth, whereas some may develop it within the first few weeks of life.
Read this post to know more about the causes, symptoms, diagnosis, treatment, and prognosis of Mongolian blue spots in babies.
What Causes Mongolian Blue Spots In Babies?
Mongolian blue spots or Mongolian spots appear due to the collection of melanocytes (pigment cells) in the skin’s deep layer. Entrapment of melanocytes in the dermis (deep layer of skin) usually occurs during embryonic development, and they fail to reach the epidermis (superficial layer of the skin). Melanocytes make skin pigment called melanin. Thus, the accumulation of these cells could result in the development of bluish or bluish-graymarks, known as Mongolian blue spots, on the skin (1).
Extensive spots might indicate inborn errors of metabolism and vascular pathologies (2). However, in most cases, Mongolian spots are benign.
The birthmark tends to be more common in people with Asian, Native American, Hispanic, East Indian, and African ethnicities. It was originally believed to have been present only in those of Mongoloid descent, hence the name.
Symptoms And Signs Of Mongolian Blue Spots
Mongolian blue spots are not painful and do not cause any serious symptoms for the babies. Parents may notice the following features of Mongolian blue spots (3).
- Blue or blue-graycolor spots that commonly appear on the back, buttock, or shoulders
- The spot may appear flat with unclear border and irregular shape
- Each spot could usually be two to eight centimeter wide
- Non-blanching (do not fade under pressure)
- The texture of the surrounding skin would be normal
The birthmark may also appear on the face, limbs, or any other part of the body and are called ectopic Mongolian spots. In rare cases, it can be mistaken for bruises that may arise due to trauma or child abuse.
Mongolian blue spots may sometimes cover large areas of the skin. However, these spots are not cancerous and are mostly benign. There won’t be any changes in the skin other than the colorof the birthmark.
Diagnosis Of Mongolian Blue Spots
Doctors can diagnose Mongolian blue spots by observing the skin. The pediatrician usually evaluates all types of birthmarks during the routine newborn examination. There is no test required to diagnose Mongolian blue spots. In rare cases, healthcare professionals may order some tests if they suspect any underlying conditions.
Treatment For Mongolian Blue Spots
Mongolian blue spots do not require treatment if they are normal birthmarks.
If the spots are due to other conditions, the treatment is prescribed accordingly. You may discuss with a pediatrician for the individual treatment plan.
Prognosis Of Mongolian Blue Spots
In many cases, the normal birthmarks may fade away by age four or during teenage. However, more extensive and persistent melanocytosis may tend to stay for several years or a lifetime.
Mongolian blue spots are not cancerous and do not require any medical intervention. These spotsare not associated with melanoma or any other types of skin cancers. You may wait for a few years for the birthmark to fade away. The birthmark does not cause pain or interfere with the baby’s growth. Nevertheless, an examination by a pediatric dermatologist is recommended to rule any underlying conditions.
2. Divya Gupta and Devinder Mohan Thappa, Mongolian spots: How important are they?; World Journal of Clinical Cases; NCBI
3. Lumbosacral Dermal Melanosis; DermNet NZ