BABY'S SKIN:
The expression "having baby's skin" is very common, and it means that one has perfect skin: soft, delicate, smooth and bouncy. If baby's skin evokes perfection, it hides one of the specificities that make it fragile. Indeed, recent research shows that at birth, even if all the components of the infant's skin are in place, it will be constantly evolving. Thus, some features of the skin barrier such as epithelial tissue, connective tissue, hydrolipidic film and the cutaneous immune system will only mature in the first year.
New research has shown that baby skin also differs from adult skin by its extraordinary cellular richness : it has a stem cell capital that is at its maximum at birth, but extremely vulnerable during the first years of life, the period of construction of the skin barrier. This cellular capital, fragile and unique for a lifetime, constitutes the life-capital of the baby's skin: it will ensure throughout its existence a role of restoration and maintenance of the overall balance of the skin. It is therefore essential to protect it, to preserve the qualities of your baby's skin for today and tomorrow.
Extremely sensitive, baby's skin is an exceptional organ of communication with the outside world.
An epidermis that is too thin
The baby's epidermis is very thin: four to five times thinner than the epidermis of an adult who measures about 2 millimeters. It is therefore very fragile. In addition, in the epidermis of a baby, the cells are very spaced, unlike that of adults who present cells together and nested in each other. This makes it much more "permeable" and open to all the elements capable of passing through it: chemicals or microorganisms such as bacteria, viruses and fungi.
In addition, in relation to weight, the skin is proportionally 3 to 5 times larger in the baby than in the adult. As a result, any substance that passes through the skin will be much more concentrated in the body, which can increase the risk of toxicity. The epidermis of a baby is also very sensitive to daily mechanical aggressions (friction of diapers and clothes) and climatic (temperature, sun ...).
A dermis too thin
Because of its collagen fibers and fine and rare elastins, a baby's dermis is three times thinner than that of an adult. Sweat glands (sweat glands) are present and active in the baby's dermis, which is not the case for sebaceous glands.
The sebaceous glands are responsible for the production of sebum, which is one of the major components of the skin's hydrolipidic film. As these glands are absent or inactive in the baby, the hydrolipidic film will not be able to be formed normally.
A defective hydrolipidic film
It is an element often underestimated, yet it plays a central role in the protection of the skin, especially against dehydration. Indeed, it prevents the water molecules contained in the epidermis from evaporating in too large quantities (Figure 1). However, the hydrolipidic film is thinner in the baby than in the adult, so thin that it is almost non-existent. Deficient in sebum and sweat, it does not sufficiently protect the epidermis against dryness and dehydration.
A baby's skin is then much more vulnerable to the aggressions of the world around it (wind, cold, sun, air conditioning). This is why babies should be avoided to be exposed to these factors. For example, no sunscreen will be more effective than an avoidance strategy for the first two years of a child's life.
Figure 1 : Diagram of dermal evaporation of cellular water
A protective hypodermis
In the first year of life, the hypodermis can contain adipocytes (fat cells) of large size and present in large numbers, which ensures the baby significant energy reserves in case of survival. This thick greasy coat also serves as a protective mattress against small shocks.
It is thanks to a dermis well supplied with fat cells that many babies are chubby and have bulges and double chin that make adults crack so much. However, this padded effect gives a false impression of solidity.
Neutral pH
At birth, the pH of the skin is close to neutrality. It then evolves to become more acidic in adults. In general, healthy adult skin has a slightly acidic pH of 5.5. This pH can vary depending on the skin type of the adult, so dry skin has a more acidic pH and oily skin has a more alkaline pH. pH neutrality makes the baby's skin more susceptible to infection and irritation.
The first contact made by baby is through the skin. It is the first sensory organ to be developed. Very thin and delicate, it is immature at birth and is not yet well prepared to face external aggressions. Although its structure is the same as in adults, its functioning and reactions are very different. This is why, from birth until maturity, baby's skin needs specific products adapted to its fragility.
