The Origin of Hyperpigmentation.
Hyperpigmentation means that areas of the epidermis are altered by an overproduction of melanin. It has an impact on the uniformity of the complexion. Some people may appreciate them and find them aesthetically pleasing, while others seek to reduce them. Find here the different origins of these dark spots.
Hyperpigmentation, an Overview.
The darkening of skin in the form of brown spots is due to a disturbance in the pigmentation process (melanogenesis). Melanin, the pigment that gives the skin its natural color, is overproduced in certain areas, which leads to the appearance of brown, red or pink spots. These pigmentation spots appear most often on the face. However, they can appear all over the body and particularly on the forearms, neckline, upper back, back of the hands and shoulders. They can affect all skin tones and types. However, they appear more frequently in people over 40 years of age and in darker skin types (IV to VI).
Dark spots are generally harmless,
but it is important to monitor them.
If they change shape, color, size or if they start to itch or bleed,
it is essential to consult a dermatologist.
What Causes Hyperpigmentation?
According to their origin, hyperpigmentation is classified in several categories:
Sun spots (lentigo or age spots), due to prolonged and repeated exposure to the sun's UV rays.
As a reminder, the production of melanin by the melanocytes increases under the action of UV rays and pigmentary anomalies can occur. They appear mainly on the parts of the body most frequently exposed. Be careful, taking certain photosensitizing drugs can promote lentigo. Lentigo can also be caused by skin aging. With age, the skin is not able to protect itself completely from external aggressions and deteriorates. We observe a dysfunction of the melanocytes associated with the exhaustion of their pigmentary potential at the level of the hair bulbs. This phenomenon is attributed to the consequences of repeated attacks by reactive oxygen species (or free radicals) on the nuclei of melanocytes and mitochondria. When this happens, the skin becomes vulnerable to UV rays, which are responsible for hyperpigmentation, then called age spots. To prevent this, at any age, it is therefore essential to apply a sun protection suited to your skin tone before exposure to the sun.
Pregnancy mask, hyperpigmentation due to hormonal variations.
Also called chloasma or melasma, these hyperpigmentation marks are caused by hormonal changes. They occur during pregnancy, but also after taking a contraceptive pill or a hormone replacement therapy. In fact, hormones stimulate melanocytes and therefore the overproduction of melanin. Note that the pregnancy mask generally disappears after childbirth, even if it may take some time.
These pigmentary marks result from an increased activity of melanocytes stimulated by pro-inflammatory cytokines after an inflammation (wounds, burns, blemishes, acne outbreaks). This type of mark is more common in mixed to darker phototypes.
Note: Pigment spots can also be of genetic origin, such as freckles, which appear at birth. This phenomenon, mostly associated with light skin, is not dangerous for the body.
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Groupe Laser de la SFD. Les taches pigmentaires (2017).