What do we need to know about AE(-) skin typology?

Cutaneous ageing: ABSENT

Oxidation factors: EXPOSED

Sebum production: LOW (−)

In the AE(-) typology, the letter “A” indicates a skin without visible signs of cutaneous ageing. This means that the skin tissue still retains its full firmness, elasticity and radiance, reflecting proper cellular function and an intact skin structure. At this stage, the network of collagen and elastin in the dermis remains dense, allowing the skin to stay smooth and springy.

The absence of visible signs of ageing does not, however, imply a lack of biological change. From the late twenties onwards, cellular renewal mechanisms gradually begin to slow down. The skin produces fewer structural proteins and moisturising molecules, such as hyaluronic acid. These changes remain unseen on the surface but constitute the first internal markers of cutaneous ageing, linked to both endogenous (genetic, hormonal, metabolic) and exogenous factors (UV radiation, oxidative stress, pollution).

AE(-) skin is therefore in a state of equilibrium, where preventative measures can delay the onset of ageing signs.

The letter “E” designates a skin subjected to an oxidising environment, that is to say subjected to repeated external aggressions, such as UV rays, atmospheric pollution, tobacco or chronic stress. These factors stimulate the production of free radicals, unstable molecules naturally generated by cellular metabolism but whose production may be enhanced by the aforementioned external pro-oxidant factors. Highly reactive, free radicals alter membrane lipids, cellular DNA and the dermal support proteins, thereby accelerating skin ageing.

Under normal conditions, the body has an endogenous antioxidant system, notably composed of vitamin E, coenzyme Q10, glutathione and enzymes such as superoxide dismutase and catalase, capable of neutralising these free radicals. However, when the amount of free radicals exceeds the skin's defensive capacity, an imbalance occurs - this is known as oxidative stress. This oxidation process can affect the skin's structure and cause its premature ageing, or even cancer. Wrinkles, initially superficial, then progressively deeper, less firm skin and a duller complexion may begin to appear, even prematurely.

For AE(-) skin, it is important to strengthen resistance to oxidative stress.

The "-" indicates that the skin exhibits a reduced sebum secretion by the sebaceous glands, also known as sebaceous hyposecretion, along with insufficient synthesis of natural moisturising factors (NMF) by keratinocytes. These compounds are essential for retaining water in the epidermis and ensuring the integrity of the skin barrier. In AE(–) skin, this deficiency manifests as sensations of tightness, irritation, fine dehydration lines, redness, flaking and a dull complexion, which are characteristic of this skin profile.

Indeed, this deficiency of fatty matter reduces the effectiveness of the hydrolipidic film. The skin then becomes more vulnerable to environmental aggressors (UV rays, pollution, bacteria…), thereby increasing the risk of inflammatory responses. Moreover, this impairment of the skin barrier causes a dysregulation of Langerhans cells, the immune system’s cells, which begin to trigger disproportionate inflammatory reactions in response to this heightened stimulus. Several factors can exacerbate this low production of sebum : overly frequent washing, unsuitable skincare products, medication, seasonal variations, exposure to UV, smoking, and genetic predispositions.

Daily exposed to environmental factors and exhibiting insufficient sebaceous activity, AE(-) skin tends to undergo premature ageing if no preventative practices are put in place.

To maintain the balance of AE(-) skin, we recommend you adopt a routine centred on hydration and the prevention of external aggressors.

• Perform a gentle cleansing.

  Even skin with low sebum production requires daily evening cleansing. To avoid compromising its barrier function, it is important to avoid water that is too hot or too cold and to favour a gentle cleansing formulation. The superfatted dermatological cleansing bars, rich in lipids, are particularly suited to these skin types.

• Hydrate and nourish the skin.

  AE(-) skin suffers from a deficiency in lipids and natural moisturising factors. Daily use of a moisturising cream rich in humectant acids, such as hyaluronic acid and glycerine, and in protective lipids, such as plant oils and ceramides, helps restore the hydrolipidic film, limit water evaporation and reduce the appearance of dehydration fine lines. In parallel, you can use a nourishing oil-based serum to further strengthen the skin barrier.

• Strengthen the skin’s antioxidant defences.

  AE(-) skin types, which are highly exposed to oxidising factors, benefit from a supply of antioxidants, for example in the form of serums. Molecules such as vitamin C, vitamin E, coenzyme Q10 or polyphenols are valuable for neutralising free radicals, thereby limiting the degradation of collagen and elastin, resulting in firmer skin and a more radiant complexion.

• Protect yourself daily from solar radiation.

  Exposure to UV radiation accelerates premature ageing and promotes pigmented spots. The application of a broad-spectrum sunscreen with an SPF of 30 or higher, even in overcast conditions, is essential to prevent the formation of lentigines and to preserve the skin’s structural integrity.