The common pigment spots are freckles, coffee spots, age spots, chloasma, zygomatic brown-green nevus, and nevus of Ota. The manifestations and causes of each type of stain are different.
Freckles: It is a hereditary skin disease, but it does not appear at birth. It usually occurs when children are 5 to 6 years old.
It increases gradually with age, and is most common on the nose and cheeks. It is heaviest in late adolescence and gradually decreases after middle age. There are more women than men. It has a significant relationship with sun exposure. In summer, the number of freckles is large and obvious, which is dark brown; in winter, it is the opposite.
Coffee spots: As the name suggests, spots are like a milk coffee color mixed with coffee and milk, with different sizes, round, oval or irregular in shape, with clear boundaries, smooth surface, no higher than the leather surface, and uniform pigment.
This is also a hereditary skin disease, mostly unrelated to sun exposure. It can appear at birth or after birth. It can occur anywhere on the body and will not go away. Cafeteria plaques can be a marker of multisystem disease, such as multiple neurofibromas.
Age spots: mostly occur in the elderly, but also in young people, usually occur in the 30 to 40 years old or later, also known as seborrheic keratosis, no self-healing tendency.
It can occur on the head, neck, and various parts of the body. The early lesions are small, flat, well-defined patches with smooth or slightly papilloma-like surfaces, light brown or dark brown. Later, the damage gradually increased, and the surface was obviously papilloma-like, and a thick layer of greasy scab could be formed. Senile plaques can be stimulated to cause inflammation and irregular proliferation of epithelial tissue.
Chloasma: Chinese medicine called liver spots. It is generally considered to be related to endocrine disorders, pregnancy, oral contraceptives, cosmetics, ultraviolet rays, etc., and is more common in women.
Chloasma is distributed symmetrically on the face, mainly on the cheeks, cheeks, nose and forehead, and sometimes in the shape of butterfly wings. According to the depth of pigmentation, it is divided into 3 types: epidermal, dermal, and mixed. The epidermal type is light brown in natural light, the dermal type is blue-gray, and the mixed type is dark brown.
Brown-cyan moles on the cheekbones: Most of them are on the cheekbones, and a few can also be found on the eyelids, nose, forehead and cheeks. Most of them are symmetrically distributed black-gray speckled pigmentation, flat on the skin surface. It belongs to dermal melanocytosis. It is more common in women and can occur in children to the elderly, and some patients have a family history.
Mole of Ota: also known as oculodermal melanocytosis, it is more common in women, and the cause of the disease is unknown. It is generally believed that there is little family history. Sun exposure, fatigue, bad mood, menstruation, and pregnancy can be aggravated.
More than 50% of cases of nevus of Ota have obvious facial skin pigment changes at birth. The distribution of age of onset shows two peaks in infancy and adolescence, and occasionally occurs late or during pregnancy.
For pigmentation, an effective solution is laser treatment. The principle of laser treatment of pigmented diseases is selective photothermal action. Specific laser parameters, such as different wavelengths, pulse widths, and energies, are used to treat specific targets or chromophores, melanin or hemoglobin.
Further reading:What are the effects of picosecond？
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