When Do Congenital Dermal Melanocytosis Lesions Resolve?

Patient Presentation
A 1-day-old male was seen in the newborn nursery. He was doing well, breastfeeding and had only lost 1% of his body weight. The past medical history showed a 39-week gestation infant born to a G1P1 Hispanic mother without any pregnancy or delivery complications.

The pertinent physical exam showed his weight was 25%, length and head circumference were 50%. He had mild facial jaundice and had a ~3 cm, ovalish, light blue-grey, non-blanching lesion on his right buttock. The buttocks, spine and anus were otherwise normal as was the rest of his physical examination.

The diagnosis of a healthy male with congenital dermal melanocytosis (CDM) was made. The parents and medical student asked questions about what the CDM was and when it would go away. The resident reassured both that it was a common lesion and usually resolved over a year or more. “It doesn’t cause any problems but your doctor will continue to watch it with you as he grows,” he reassured the parents.

Discussion
Congenital dermal melanocytosis (CDM), also known as mongolian spots, are one of the most common dermal findings in infants and are often overlooked because they are so common. They commonly present at birth or soon after, and usually fade over the next few months and most are gone by 18 years. They are a grey/blue/black color that is non-blanching, usually with irregular borders and commonly appear in the lumbosacral area. They can occur in other locations including the back, extremities, abdomen and much less commonly, the face. The prevalence and incidence varies greatly among different races with CDM being less common in Caucasians and much more common in Black and Asian races. Superimposed lesions (i.e. CDM on top of another skin finding) does occur but is less common. Persistent, atypical CDM has been associated with lysosomal storage diseases and cleft lip. The differential diagnosis includes blue nevus, bruising/child maltreatment, capillary hemangioma, and oculodermal melanocytosis (Nevus of Ota).

Learning Point
A prospective study with followup of 1 year for 2313 infants in a tertiary care center in India found the following CDM characteristics: The authors note they have a diverse patient population that includes patients from all over India including those descended from different races.

Number 1 patch = 51.8% > 1 patch = 48.2% NA NA
Size < 5 cm = 61.1% 5-10 cm = 33% > 10 cm = 5.8% NA
Shape Irregular = 64.4% Oval = 16.8% Round = 7.8% Multiple shapes= 10.9%
Color Blue-green = 37.9% Dark blue = 31.9% Light blue = 23.3% Blue-black = 6.9%
Location at birth Sacral only = 78.9% Sacral & extrasacral = 18.3%

Extremities = 78.6% esp. lower

Extrasacral only = 2.7% NA
Resolution at 4 months Persisted = 75.4%% Fading = 11.5% Resolved = 13.1% NA
Resolution at 1 year Persisted = 43.5% Fading = 42.3% Resolved = 14.2% NA

This study also had 1 patient with superimposed skin findings. This has been reported in other studies.

Questions for Further Discussion
1. What are common skin lesions for major phakomatoses? A review can be found here
2. When is jaundice abnormal? Additional cases can be reviewed here
3. What is the natural history of capillary hemangiomas?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: BirthMarks

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Gupta D, Thappa DM. Mongolian Spots – A Prospective Study. Pediatr Dermatol. 2013;30(6):683-688. doi:10.1111/pde.12191

Musumeci ML, Lacarrubba F, Santagati C, Micali G. Multiple and superimposed Mongolian spots. BMJ Case Rep. 2013;2013:bcr2013200740. doi:10.1136/bcr-2013-200740

Alimi Y, Iwanaga J, Loukas M, et al. A comprehensive review of Mongolian spots with an update on atypical presentations. Childs Nerv Syst ChNS Off J Int Soc Pediatr Neurosurg. 2018;34(12). doi:10.1007/s00381-018-3929-0

Sharawat IK, Suthar R, Ahuja CK, Sankhyan N. Extensive Bluish-Black Spots. J Pediatr. 2018;198. doi:10.1016/j.jpeds.2018.02.067

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa