PE(-) skin typology: what are its characteristics?

Cutaneous ageing: PRONOUNCED

Oxidation factors: EXPOSED

Sebum production: LOW (-)

In the PE(-) classification, the letter P denotes the visible and well-established appearance of time’s marks. This development results from a combination of biological mechanisms: the gradual decrease in the synthesis of collagen and elastin, fragmentation of existing fibres, loss of hyaluronic acid and alteration of epidermal lipids. With age, fibroblasts become less active, their ability to produce a dense, functional extracellular matrix diminishes, and the quality of the dermis is altered. The skin progressively loses elasticity and resilience, promoting the formation of pronounced wrinkles and visible skin laxity.

This phenomenon is also amplified by internal processes, such as glycation, which stiffens collagen fibres, and by low-grade chronic micro-inflammation, which accelerates structural alterations. In PE(-) skin, these changes often present as deep wrinkles, a loss of density, a less even skin texture and reduced radiance. The epidermis becomes thinner and less capable of retaining the water, which further accentuates the visibility of the signs of skin ageing.

In a PE(-) profile, the letter E indicates that the skin is repeatedly exposed to the influence of pro-oxidant factors : UV radiation, atmospheric pollution, tobacco, chronic stress or even insufficiently protected sun exposure. These various elements increase the production of free radicals, unstable molecules capable of directly interacting with membrane lipids, structural proteins and DNA. When these free radicals exceed the skin’s natural antioxidant defences, an imbalance sets in: this is oxidative stress. This process gradually weakens the cohesion of the epidermis, compromises the extracellular matrix and accelerates skin ageing.

This repeated exposure to oxidative factors to which PE(-) skin is exposed is compounded by a cutaneous structure already weakened by established signs of ageing.

The “–” sign indicates that the sebaceous glands of the dermis produce only small amounts of sebum, yet this is essential for maintaining the integrity of the skin barrier. Indeed, the sebum is not merely an oily film on the surface: it is a complex blend of lipids (squalene, fatty acids, triglycerides and wax esters) that contributes to the formation of the hydrolipidic film, an important component of skin biology that helps to limit water evaporation from the stratum corneum and to protect the skin from external aggressors. When this film is insufficient or compromised, the stratum corneum loses cohesion, intercellular lipids become depleted and the barrier function becomes more permeable. This increased permeability facilitates the penetration of environmental irritants and increases water loss.

In a PE(-) profile, this low sebum secretion exacerbates phenomena already weakening the skin related to the signs of ageing and oxidative stress. The lack of lipids slows the skin’s natural repair mechanisms and leaves it less able to cope with external stressors such as wind, cold or pollution. Visually, this appears as a finer texture and a surface that may feel rough in places and a tendency towards dehydration fine lines that are more prominent, adding to the deeper wrinkles.

PE(-) skin requires a skincare strategy that reinforces its skin barrier, neutralises oxidative stress and helps mitigate the signs of ageing.

In the morning, the priority is to protect the skin. This is achieved by supplying it with active ingredients that limit oxidative processes and reinforce its hydrolipidic film. A very gentle cleanser first removes overnight perspiration whilst preserving its already low sebum content. The application of an antioxidant serum, containing for example vitamin C or ferulic acid, helps reduce the impact of free radicals to which PE(-) skin is particularly exposed. Next comes a cream containing biomimetic lipids, such as the ceramides, or squalane, to rebuild the cohesion of the skin barrier. Finally, daily sun protection is essential to limit the oxidation induced by UV rays.

In the evening, the routine aims to nourish the skin more deeply and combat the signs of ageing. After make-up removal, for example with a cleansing oil, a treatment that preserves the skin’s lipids, and a gentle cleanse, for instance with a superfatted dermatological cleansing bar, particularly useful for cleansing the skin without drying it out, the skin is then ready to receive treatments. This is the time to use a hydrating serum, which may contain hyaluronic acid or glycerin, and a firming treatment, perhaps containing retinoids or peptides. Finally, a rich cream helps seal in hydration and promote the skin’s overnight regeneration.