Hyperpigmentation, due to excessive production of melanin by the skin, is harmless but can be aesthetically embarrassing. Lightening products are numerous but the main prevention remains optimal sun protection.

Pigmentation of the skin is the result of the production of melanin. This phenomenon is called melanogenesis. It is controlled by different factors:

• The genetic factor: the color of the skin depends on a set of genes which determine the type and level of melanins synthesized;
• The hormonal factor: certain hormones are capable of stimulating melanogenesis (MSH, ACTH, estrogen and progesterone);
• UV rays: UVA and UVB solar radiation can act directly on melanocytes or indirectly by stimulating the production by keratinocytes of mediating agents;
• The other factors: any damage to the skin: irritation, friction, use of unsuitable cosmetics and any process causing an inflammatory reaction.

Hyperpigmentation occurs when melanin is produced in excess in certain areas of the skin. There are then dark spots more or less large on the skin.

This overproduction results from a number of factors: excessive exposure to the sun, age, hormonal variations, genetic predispositions or even skin trauma. Depending on the triggering factor, hyperpigmentation takes different forms.

Scars, moles, birthmarks or the consequences of skin cancer, although causing the appearance of dark spots, are not considered to be a form of hyperpigmentation.

Hyperpigmentation is characterized by the appearance of more or less dark spots, localized or generalized on the whole body. The cause of these symptoms depends on the shape and color of the spots. 

We can recognize several types of hyperpigmentation:

• Lentigos. They are usually small and dark, round or oval spots. Lentigos can be related to age (senile lentigines or age spots) or excessive sun exposure (solar lentigines). This is why they mainly appear on frequently exposed parts of the body, such as the face, hands and arms;
• Melasma or chloasma. Also called “pregnancy mask”, it affects 90% of pregnant women. It results from hormonal phenomena such as pregnancy and the effects of the contraceptive pill, and results in the appearance on the face or arms of dark and irregularly shaped areas which can be relatively large;
• Post inflammatory pigmentations. These are residual hyperpigmented spots that persist after the healing of various dermatoses (acne, infectious or inflammatory dermatoses). They are particularly frequent in subjects sensitive to acne, of dark phototype or after sun exposure;
• Phototoxic reactions. Some hyperpigmentation can be caused by phototoxic reactions to perfumes or certain drugs;
• Other factors can also be involved in hyperpigmentation, such as diseases promoting the hypersecretion of the hormone stimulating the formation of melanin (adrenal insufficiency, certain lung and pancreatic cancers). Hemochromatosis, poisoning with arsenic, lead, gold salts, mercury can also promote hyperpigmentation.

Hyperpigmentation is harmless. However, some people wish to make them disappear for aesthetic reasons.

There are currently various possibilities for treating pigmentation disorders:

• Dermatological preparations specially designed for this purpose such as creams can contribute to the lightening or disappearance of the hyperpigmented parts.
• Exfoliating treatments promote the elimination of pigmented cells and also promote the penetration of depigmenting active ingredients.
• Superficial chemical peels based on alpha hydroxy acids are common treatments and are generally well tolerated. Chemical peels work by promoting the exfoliation and dispersion of the basal layer of melanin. Excessive irritation can lead to additional hyperpigmentation, so it is important to choose the ingredients for your treatment carefully, taking into account skin type and any allergies and / or sensitivities.
• Lentigos can be treated with liquid nitrogen cryotherapy or laser therapy.

The healing process is unique to each person, it can vary widely depending on skin color, the severity of the post-inflammatory hyperpigmentation and the treatments. In some cases, the hyperpigmentation spots can remain long term or permanently. For some people, especially those with darker skin tone, a minimum of 3-6 months of treatment is required before significant improvements are seen.

Protecting your skin from the sun is the main prevention of aging hyperpigmentation or acne. The use of full screen at each exposure is recommended to avoid aggravating an already present hyperpigmentation. Anti-inflammatory treatments also make it possible to prevent new inflammations of the acne type on surfaces affected by hyperpigmentation.