What is the cause of baby melanin nevus

Melanoma moles are something we often see in our daily lives. Many people have many on their faces, most of which are caused by not paying attention to hygiene habits, diet, etc. But how do babies grow? It can actually be divided into two types: congenital and acquired. Most of them are flat, granular and composed of some black and brown pigment cells. Today I will tell you what baby melanocytic nevus is.

Melanoma

Congenital moles are mostly present at birth or in the neonatal period, while acquired moles may appear after six months of age until old age.

Acquired moles are usually 0.1 to 0.6 cm in size and can be pathologically divided into three types: junctional nevus (nevus cells are confined to the junction of the epidermis and dermis, which are intraepidermal nevus), compound nevus (nevus cells are not only distributed in the epidermis, but also extend down to the dermis), and intradermal nevus (nevus cells are completely located in the dermis). The clinical appearance of a mole is also related to its pathological classification. Junctional nevi appear as flat brown to black spots that do not protrude from the skin surface. Compound nevi usually appear as brown raised papules or nodules. Intradermal nevi are larger and more raised, appearing as light brown or flesh-colored nodules, which are what people generally call dermal nevi.

Classification of melanocytic nevus

Congenital melanocytic nevus can be found in 1% to 2% of newborns, but the incidence of giant congenital melanocytic nevus is less than one in 20,000 (foreign statistics). Clinically, melanocytic nevi can be divided into three types according to their size:

Small melanocytic nevi: less than two centimeters in size, preferably distributed on the lower body, upper back, shoulders, chest and proximal limbs.

Intermediate melanocytic nevus: The size ranges from 2 to 20 cm.

Giant melanocytic nevus: It is larger than 20 cm in size and is mainly distributed on the back half of the trunk. Some people may have it on the head or limbs. It may cover large areas of skin on the body. They are usually dark in color and lightly covered with hair, with satellite lesions scattered around the main mass.

Most congenital giant melanocytic nevi are benign, but congenital giant melanocytic nevi are usually more complicated than acquired giant melanocytic nevi. According to its growth pattern, it can be divided into three types:

Compound or intradermal nervus: most common.

Neural nervus: A neural tube or neuroma may be present in the structure and may look like a neurofibroma.

Blue nervus: the least common.

Melanoma must be clinically distinguished from melanoma, which is the type of skin cancer with the highest mortality rate, accounting for about two-thirds of all skin cancer deaths. According to Western statistics, approximately 20% to 50% of melanomas are related to moles. Therefore, it is very important to distinguish whether a mole is complicated by melanoma. Generally, they are distinguished according to ABCDE. A stands for Asymmetry, which means the lesion is asymmetrical up and down or left and right (imagine that the lesion can be folded up and down or left and right like origami); B stands for Border Irregularity, which means the edge does not form an arc shape but has jagged notches; C stands for Color Variability, with some parts having dark pigmentation and some parts having light pigmentation; D stands for Diameter >6mm, which means the diameter of the lesion is greater than 0.6 centimeters; E stands for Elevation or Enlargement, which means the surface becomes raised or the size of the lesion increases. Any lesion that is medically suspected of being malignant must undergo biopsy and pathological examination. Fortunately, melanoma and moles are much less common in Asians than in Caucasians.

Cause prevention

Causes

Ultraviolet rays are a major cause of melanin formation. In daily life, if you do sun protection while performing whitening care, you can effectively inhibit the formation of melanin. Because during whitening care, the melanin that has already been produced can be slowly eliminated, and sunscreen can help the skin inhibit the production of new melanin. By using good sunscreen products to protect the skin's basal layer and dermis from damage by ultraviolet rays and not stimulating the activity of tyrosinase, the production of melanin can be inhibited. The slow alternation of new and old cuticles is also one of the reasons for the formation of melanin. Therefore, regular exfoliation is very helpful for whitening the skin. The acidic substances added to many whitening products can help peel off aging cuticles and remove melanin.