Understand the skin Part 2: the dermis

The vast majority of us are constantly looking for new products to discover to improve the appearance of our skin. Cream, exfoliant, cleanser, mask, foundation, etc., there are more product classes than letters of the alphabet, and all without exception claim to have an impact of near or far on the skin. So we thought that it would be interesting and especially relevant to understand what is made of the skin and how this organ works! In 2 parts ... we present you: the skin.

The dermis is the second layer of the skin, it is just below the epidermis. Understanding how this structure works is very interesting from a cosmetic point of view because it allows us to be critical of the products we plan to buy.

The dermis is responsible for the support of the skin as well as its elasticity and flexibility. It also plays an important role in the nutrition of the epidermis as well as in the healing of the skin.

It is in the dermis that the hair follicles, the sweat and sebaceous glands, blood vessels and various fibers are located. It is formed among others of collagen, elastin, glycoproteins and water.

Collagen is one of the strongest and most abundant proteins in the human body. At the level of the skin, it plays a key role in its durability and resilience. With age, it is known that collagen decreases. This protein and its link with the appearance of the skin have been studied many times. Many cosmetics, both topical and injections, are intended to stimulate its production or to literally replace and repair it. However, it is advisable to remain cautious about the miracle results promised by these different products, especially those of topical creams. Indeed, several molecules are too big and can not penetrate the dermis!

Elastin (a protein) provides resilience and elasticity to the skin and other organs including the lungs and blood vessels. It is among other things that allows the skin to stretch and recover afterwards. The synthesis of elastin begins during the fetal phase and reaches its maximum in the neonatal period. It decreases significantly after that and is almost non-existent in adulthood. This is one of the reasons, among others, the appearance of wrinkles during aging. Briefly, the dermis loses elasticity and tone, and in fact, is less and less able to oppose muscle contractions ... which leads to fine lines and wrinkles. Also note that UV rays increase the degradation of elastin ... so do not forget your sunscreen!

While the epidermis is the target of the vast majority of topical cosmetics, the dermis is that of several injectable treatments. This is so since the majority of topicals can not penetrate the dermis, and must therefore be injected to get there. Remember that the dermis is extremely important for the appearance of the skin! He is responsible for his support, his elasticity as well as his flexibility. A decrease in its main components, including elastin and collagen cause aging of the skin. It is therefore not surprising that many cosmetics try to delay the decrease or literally replace these constituents. However, let's be very careful before believing in all the effects promised by our cosmetics. Let's be critical and knowledgeable!

Baumann, L. Cosmetic Dermatology, 2nd edition, 2009.

Seite S, Zucchi H, Septier D, Igondjo-Tchen S, Senni K, Godeau G., Elastin changes during chronological and photo-aging: the important role of lysozyme. J Eur Acad Dermatol Venereol. 2006 Sep; 20 (8): 980-7.

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