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

Cutaneous aging: ABSENT

Oxidation factors: EXPOSED

Sebum production: LOW (-)

In the AE(-) classification, the letter "A" indicates a skin without visible signs of cutaneous aging. This means that the skin tissue still retains 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 resilient.

The absence of visible signs of aging does not, however, necessarily imply a lack of biological change. By the end of the twenties, cellular renewal mechanisms gradually begin to slow down. The skin produces fewer structural proteins and hydrating molecules, such as hyaluronic acid. These changes remain invisible on the surface but represent the first internal markers of skin aging, linked to both endogenous factors (genetic, hormonal, metabolic) and exogenous ones (UV rays, oxidative stress, pollution).

AE(-) skin is thus in an equilibrium phase, where preventive measures can delay the emergence of aging signs.

The letter “E” denotes a skin exposed to an oxidizing environment, that is, repeated external assaults such as UV rays, air pollution, tobacco smoke, or chronic stress. These factors stimulate the production of free radicals, unstable molecules naturally generated by cellular metabolism but whose production can be amplified by the aforementioned pro-oxidative external factors. Highly reactive, free radicals damage membrane lipids, cellular DNA, and the dermal support proteins, thereby accelerating skin aging.

Under normal circumstances, the body has an endogenous antioxidant system—primarily vitamin E, coenzyme Q10, glutathione, and enzymes such as superoxide dismutase and catalase—that can neutralize these free radicals. However, when free radical levels exceed the skin’s defense capacity, an imbalance occurs: this is known as oxidative stress. This oxidation process can disrupt the skin’s structure and cause its premature aging, or even cancer. Fine lines—initially superficial, then progressively deeper—less toned skin, and a duller complexion can begin to emerge, and this can occur prematurely.

For AE(-) skin, it is important to strengthen its 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 moisturizing factors (NMF) by keratinocytes. These compounds are essential for retaining water in the epidermis and maintaining the integrity of the skin barrier. In AE(-) skin, this deficiency manifests as tightness, irritation, fine dehydration lines, redness, flaking, and a dull complexion—hallmarks of this skin profile.

Indeed, this lack of lipids reduces the effectiveness of the hydrolipidic film. The skin then becomes more vulnerable to aggressors (UV rays, pollution, bacteria...), which increases the risk of inflammatory reactions. Moreover, this alteration of the skin barrier causes dysregulation of Langerhans cells, the immune system’s cells, which begin to trigger disproportionate inflammatory responses in reaction to this significant stimulation. Several factors can exacerbate this low production of sebum : too frequent washing, inappropriate skincare, medication treatments, seasonal variations, UV exposure, smoking, and genetic predispositions.

Exposed daily to environmental factors and exhibiting insufficient sebum production, AE(-) skin tends to age prematurely if no preventive practices are implemented.

To maintain the balance of AE(-) skin, we recommend adopting a regimen focused on hydration and protection against external stressors.

• Perform a gentle cleansing.

  Even skin with low sebum production requires a daily evening cleansing. To avoid compromising the skin barrier, it is important to avoid water that is too hot or too cold and to opt for a gentle surfactant-based cleanser. The lipid-rich dermatological bars, rich in lipids, are particularly well suited to these skin types.

• Hydrate and nourish the skin.

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

• Strengthen the skin’s antioxidant defenses.

  AE(-) skin, which is highly exposed to oxidative stress factors, benefits from the addition of antioxidants, for example in the form of serums. Molecules such as vitamin C, vitamin E, coenzyme Q10, or polyphenols are effective at neutralizing free radicals, thereby limiting the degradation of collagen and elastin for firmer skin and a more radiant complexion.

• Protect yourself daily from solar radiation.

  UV exposure accelerates premature aging and promotes pigmented spots. Applying a broad-spectrum SPF 30 or higher sunscreen, even on cloudy days, is essential to prevent the formation of lentigos and to preserve the skin’s structural integrity.