Introduction
Dermal melanocytosis refers to a particular birthmark kind that is flat, blue, or blue-gray. They emerge throughout the first few weeks of life or at delivery. Dermal melanocytosis is also known as the Mongolian spot or slate grey nevus. It is a typical congenital (existing from birth) disorder that results in infantile pigmented lesions due to excessive cutaneous melanocyte production, the skin pigment (melanocytosis). The most typical sites of congenital cutaneous melanocytosis are the shoulders, the lumbar, and the sacral-gluteal areas. They affect persons of both sexes equally, are most common in Asian and Black people, and disappear between the ages of one and six. The majority of benign congenital cutaneous melanocytosis does not require treatment.
What Are the Causes of Dermal Melanocytosis?
Congenital dermal melanocytosis is caused by improper migration and aberrant melanocyte clearance from the dermal layer during fetal development. According to studies, hereditary metabolic disorders and aberrant congenital dermal melanocytosis are related.
What Is the Prevalence of Dermal Melanocytosis?
Congenital cutaneous melanocytosis is equally common in both sexes. Lesions typically appear in patients at birth or soon after, and they typically disappear by the time they are six years old. The largest prevalence is among Asian and Black people. More than 90 percent of offspring of the mongoloid race are born with the patches. Other races experience them less frequently.
How Does Dermal Melanocytosis Occur?
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By ten weeks of gestation, neural crest cells in the fetus give rise to melanocytes.
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Between weeks 11 and 14, these cells can be found in the dermis of an embryo.
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By week 20 of pregnancy, neither migration nor macrophage clearance should have left any melanocytes in the dermal layer.
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Congenital dermal melanocytosis is an increase in melanocytes that actively produce melanin in the dermis.
Tyndall's Effect -
Dermal melanin scatters the shorter wavelengths of blue light in this effect, which reflects off the skin's surface and gives the skin a blue-gray tint. Additionally, a fibrous extracellular sheath protects the cutaneous melanocytes. However, this sheath eventually vanishes and is removed during fetal life and the first few months of infancy.
What Are the Symptoms of Dermal Melanocytosis?
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Congenital dermal cutaneous melanocytosis is commonly found on the sacral, lower lumbar, or gluteal surfaces. It appears as a single or many hyperpigmented macular lesions.
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Most cases involve less than five percent of the total body surface area and may develop during pregnancy or soon after birth.
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The lesion has a variety of colors, including blue, dark grey, and blue-green, with an uneven, circular, or oval shape.
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Extra-sacral aberrant lesions can develop on the lower extremities, groin, upper extremities, shoulder, and chest.
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Lesions caused by congenital cutaneous melanocytosis often disappear by age one and rarely last until age six.
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Lesions with an extra-sacral position, a diameter of more than 10 cm, or a deeper hue are more likely to recur after one year.
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The clinician will help make the right diagnosis by asking parents or carers about when the lesions first appeared. Congenital cutaneous melanocytosis should not be mistaken for another potential diagnosis.
What Is Lumbosacral Dermal Melanocytosis?
A blue-gray skin stain known as Mongolian spot, which typically appears on newborn babies' lower back and buttock region, is called lumbosacral dermal melanocytosis. It is a typical variety of birthmarks. Symptoms of lumbosacral cutaneous melanocytosis include bluish-gray spots on the buttocks or lower back. Dermal melanocytosis can also affect different areas, such as the face or limbs. The patches may get larger but are typically a few centimeters in diameter. Except for color, the affected skin is not thickened or altered in any other manner.
What Is Oculodermal Melanocytosis?
Oculodermal melanosis, often referred to as oculomucodermal melanocytosis, is a benign mesodermal melanosis that affects the maxillary and ophthalmic trigeminal nerve distributions, resulting in gray-blue macular hyperpigmentation of the conjunctiva, sclera, and ipsilateral face skin. This happens due to unilateral melanocyte entrapment in the top section of the dermis. Scleral involvement occurs in more than two-thirds of cases, and this disease is associated with an increased risk of glaucoma. Rarely, the inside of the mouth may be affected by the same pigmented lesions that affect the palate.
How Is Dermal Melanocytosis Diagnosed?
A benign disorder, congenital cutaneous melanocytosis does not require additional laboratory, radiographic, or histologic testing. However, nevus of Ota (oculodermal melanocytosis) requires ophthalmological evaluation, particularly if the sclera is involved.
Slit Lamp Biomicroscopy -
It should be performed to assess the eyelids since it can distinguish between conjunctival and episcleral pigmentation. In addition, the angle structures may have hyperpigmentation.
Dermoscopy -
A noninvasive technique enables the evaluation of the papillary dermis, dermo-epidermal junction, and colors and microstructures of the epidermis that are not visible to the human eye.
Dilated Ophthalmoscopy -
It can reveal glaucomatous optic nerve cupping and asymmetric darkening of the vasculature.
What Is the Management for Dermal Melanocytosis?
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These birthmarks provide no health risk because they are not malignant. However, to be sure of the diagnosis, the child's pediatrician should check the marks.
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No medical intervention is required or advised. There are no health issues resulting from the spots.
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Congenital cutaneous melanocytosis often disappears within a year and rarely returns after age six.
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Extra-sacral lesions, however, can be treated for aesthetic reasons with a 755-nm Q-switched alexandrite laser.
What Is the Prognosis for Dermal Melanocytosis?
Congenital cutaneous melanocytosis rarely lasts past the first ten years of life and does not develop into a malignant condition.
Conclusion:
Congenital dermal melanocytosis is a benign condition that does not need any additional testing or care. Parents are informed that this condition should go away by the time their child turns one and rarely lasts past six. Laser therapy is a potential alternative for cosmetic treatment if extra-sacral lesions continue. While congenital dermal melanocytosis is a benign condition that frequently resolves on its own within the first decade of life, medical professionals must be able to spot lesions that are out of the ordinary for the condition because they may indicate physical abuse or another pathology that requires further testing.
