Skin disease in a child: Mongolian blue spot (Slate Grey Nevus) Flashcards
Define Mongolian blue spot.
Macular blue-gray pigmentation usually on the sacral area of healthy infants. Mongolian spot is usually present at birth or appears within the first weeks of life. Mongolian spot typically disappears spontaneously within 4 years but can persist for life.
Explain the aetiology/risk factors for Mongolian blue spot.
Mongolian spot is congenital, developmental condition exclusively involving the skin. Mongolian spot results from entrapment of melanocytes in the dermis during their migration from the neural crest into the epidermis. This migration is regulated by exogenous peptide growth factors that work by the activation of tyrosine kinase receptors. It is postulated that accumulated metabolites such as GM1 and heparin sulphate bind to this TK receptor and lead to severe neurologic manifestations and aberrant neural crest migration.
Associated with cleft lip, spinal meningeal tumour, melanoma, phakomatosis pigmentovascularis types 2 and 5 and Sjogren-Larsson syndrome.
Summarise the epidemiology of Mongolian blue spot.
Prevalence varies among different ethnic groups. Most common among Asians. Reported in 80% of East African children, in 46% of Hispanic children, and 1-9% of white children. Usually present at birth, but it can also appear within the first weeks of the neonatal period.
What are symptoms of Mongolian blue spot?
Asymtomatic bluish discoloration overlying the sacrococcygeal area is present at birth.
What are the signs of Mongolian blue spot?
Consist of blue-grey macular pigmentation. It is a few centimeters in diameter, though much larger lesions also can occur. Lesions may be solitary or numerous. Most commonly involve the lumbosacral area, but the buttocks, flanks, and shoulders may be affected in extensive lesions.
What are appropriate investigations for Mongolian blue spot?
Usually, lab studies not indicated, except when extensive Mongolian spots are present.
In extensive Mongolian spots involving the back, radiographic studies are needed to rule out a spinal meningeal tumour or anomaly.
What is the management of Mongolian blue spot?
Opaque cosmetics may be used as camouflage for Mongolian spots.
Intense pulsed light is also an effective method for the treatment of aberrant Mongolian spots.
What are complications associated with Mongolian blue spot?
Cosmetic concerns, reoccurance.
What is the prognosis of Mongolian blue spot?
Mongolian blue spot is not associated with mortality and morbidity. Mongolian spots usually fade in the first year of life, but, at times, they may persist indefinitely.
However, melanocytes may persist in the dermis when examined histologically.
