Expert file
epidermal hyperpigmentation
Definition
Epidermal hyperpigmentation corresponds to the overproduction of melanin in some skin areas, leading to the formation of blemishes. Hyperpigmentation corresponds to an increased melanin deposit, most frequently in the epidermis and more rarely in the dermis. These deposits may be localized or generalized to the entire integument. Hyperpigmentation is caused by melanin overproduction by epidermal melanocytes, sometimes associated with reduced melanin digestion by keratinocytes in Caucasian individuals.
1 - Hyperpigmentation, a benign build-up of melanin
It leads to the appearance of diffuse generalized or localized pigmentation, or to the appearance of brown spots in areas where excess melanin is produced. these spots, darker than the skin's natural colour, can be of various sizes and shapes. they are painless and benign, though frequently considered unsightly.
2 - Main factors
Brown spot appearance is promoted by: exposure to sun, genetics, age, hormonal phenomena, pre-existing inflammatory or infectious skin lesions (cuts, burns, irritation, acne, psoriasis, eczema, etc.), and by taking certain medications or treatments.
3 - Differents types of hyperpigmentation :
Freckles
Freckles, sometimes called ephelides, which generally appear during childhood, particularly on fair skins. their number and colour increases following exposure to sun and they are more visible in summer than in winter.
Melasma also know as chloasma
Melasma is a symmetrical hyperpigmentation of the face. this condition may disappear spontaneously after giving birth, or upon termination of oral contraceptives, or in some cases, it may become chronic and persist, generally for several decades. melasma mainly affects women and occurs in more than one third of pregnant women (chloasma). existing treatments are effective for reducing or erasing virtually all lesions, though even the slightest sun exposure will cause the melasma to reappear. Clinical expression of melasma is generally seasonal: winter improvement and summer aggravation. Sun protection is an essential precaution when managing melasma.
Senile lentigo
Senile lentigo, also known as liver spot, is a small flat brown spot of a few millimetres in diameter found most frequently in uncovered parts of the skin (mainly the face, back of the hands and forearms).
Actinic or solar lentigo
Artinic is associated with excessive exposure to the sun. these spots appear on the most frequently exposed parts of the body, such as the face, hands and arms.lentigo generally occurs in fair-skinned individuals.
Post-inflammatory hyperpigmentation
Mainly observed on dark skins, this is generally a reaction to inflammation (such as acne, atopic dermatitis or psoriasis), or to an injury (e.g.: triggered by dermabrasion, chemical peeling or laser treatments). the skin remains darker in affected areas as long as inflammation persists.
4 - How is hyperpigmentation treated
Most frequently chosen option
Use of medical or cosmetic depigmenting creams that may contain various active substances that reduce melanin production or stimulate its degradation, such as: hydroquinone, arbutin, kojic acid, vitamin c derivatives, retinoic acid, licorice extract, aha, azelaic acid, etc.
Dermatological treatments
> Chemical peeling
This is a chemical exfoliation performed using an acidic solution applied to the skin with a brush. this application causes a more or less deep desquamation of the pigmented epidermis.
> Laser
Basically, the laser heats the pigmented areas, promoting their elimination.
> Dermabrasion
This process generates mechanical abrasion via a wheel, enabling the more or less deep elimination of the various layers of hyperpigmented epidermis.
> Cryotherapy
Epidermal refrigeration by applying liquid nitrogen induces a variable degree of necrosis, allowing elimination of the pigmented epidermis.
Whatever the option chosen, sun protection is essential to limit the risk of spot appearance or aggravation.
5 - Tips for limiting spot appearance
- Avoid prolonged sun exposure, wear a hat and wide sunglasses
- Every two hours, apply high-protection sun cream (SPF index: 50+),
6 - Frequent ask questions
a. How long do depigmenting creams take to act?
You must be patient a wait a few months before seeing any significant spot fading
b. Will a sun cream with a 50 index prevent me from tanning?
SPF 50 does not provide total protection, you can thus get a tan. it does, however, reduce the dose of uvb received by the skin by a factor of 50.
c. Can spots reappear after having been treated?
Yes. to avoid their recurrence, you should protect yourself from the sun with a high index sun screen.
d. How can i avoid the appearance of spots after a scar?
As soon as a small wound appears, you should use a reparative cream to ensure rapid wound healing and to limit the size of the residual scar.
Avoid exposing recent scars to the sun unprotected