Hyperpigmentation: causes and treatment

Hyperpigmentation appears when an excess of melanin is produced in the skin, which is what gives rise to spots on the skin. It can have various origins, both endogenous (genetic, hormonal, senile, post-inflammatory, metabolic, vascular, etc.) and exogenous (exposure to UV rays, pollution or other external aggressions, taking medications or medical-aesthetic treatments).

Types of hyperpigmentation

· Melanotic: There is a normal number of melanocytes and an increase in the pigment of the melanocyte. Some aesthetic pathologies:

o Ephelides (freckles). In most cases these are genetic, and typically appear in the parts of the body most exposed to the sun (phototypes I and II). Melanin increases, although the melanocytes are normal.

o Solar lentigo. They are hyperpigmentations with a flat, round shape, very small and with a shade between yellowish and dark brown, sometimes even black. They are produced by an excess of production in melanin synthesis. They are in areas exposed to the sun and are stimulated by UV radiation.

o Melasma. There is a melanin increase as the number of melanocytes increases. It is usually located in the forehead/nose, cheeks, nose, and lower jaw. It is usually caused by a hormonal factor such as pregnancy (second month), estrogens and progestogens, ovarian dysfunction, and thyroid dysfunction, along with solar radiation. Melasma is aggravated by sun exposure.

· Melanocytic. When there is an increase in the number of melanocytes. For example:

o Senile lentigo. These are small dark yellow spots that tend towards brown. They appear in large numbers from an adult age, and specifically on the hands and wrists.

· Non-melanocytic. These are caused by different factors such as tattoos, drugs (minocycline), metals (silver salts), etc. They are produced by a reaction of the skin with solar radiation (especially UV rays) when it meets areas of the skin exposed to these substances.

· Post-inflammatory hyperchromia. They occur after an acute or chronic inflammation such as eczema, acne and skin trauma of various origins.

· Endogenous imperfections of vascular origin: Couperose, rosacea, dilated capillaries, or congestive skin…

Tranexamic acid, an excellent active ingredient against hyperpigmentation

One of the most innovative and multifunctional active ingredients on the market in the field of aesthetic pathologies related to spots on the skin of various origins is tranexamic acid. It is a haemostatic agent, a synthetic derivative of the amino acid lysine that intervenes in the melanin production process and in the release of the vascular and inflammatory component of skin blemishes.

How tranexamic acid works

Tranexamic acid has several effects that influence the staining formation process.

On the one hand, it decreases the activity of tyrosinase, an enzyme on which the melanin synthesis process depends.

It also inhibits plasmin and the binding of plasminogen to keratinocytes. These two actions are what allow the elimination and prevention of hyperpigmentations such as melasma, age spots, freckles, etc.

Lastly, it inhibits vascular factors by reducing the expression of vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1), which results in an action on blood vessel cells. With this action it reduces the excessive vascularization characteristic of some hyperpigmentations: couperose, rosacea, dilated capillaries, or congestive skin, etc.