Dryness and dehydration
Whatever your skin type, specific factors might trigger or lead to oversensitivity: Your skin reacts strongly when you’d rather it didn’t…
Dryness and dehydration
WHAT A DESHYDRATED SKIN ?
Whether you have naturally dry, combination, normal or oily skin, it can become dehydrated by environmental aggression.
Certain types of skin are naturally better hydrated or less dry than others. Dry skin, whether simple xeroses, xeroses from atopic dermatitis, or ichthyosis, contains much less water than normal skin. This dryness is caused by irregularities in lipid (ceramides) or protein metabolism (proteases, filaggrin) or even by epidermal differentiation problems.
- Simple xeroses are the most common. These are easily corrected by applying emollients.
- Senile xerosis: is more pronounced on the limbs.
- Winter xerosis occurs when simple xerosis is intensified with cold and wind.
- Induced xerosis refers to skin dehydrated by cleansing products that contain overly harsh surfactants (soaps). In the same way, irritant treatments (retinoids, fruit acid) dry out the skin.
DRY SKIN DISORDERS :
- Atopic xerosis: atopic dermatitis or infantile eczema includes dryness of the skin that is more or less intense. Linked to structural irregularities in the epidermis, this type of dryness is responsible for the penetration of allergens and for water loss through the epidermis.
- Some severe nutritional deficiencies can provoke or worsen dryness of the skin.
- Some general diseases can cause the skin to become dry.
- Ichthyoses: these are rare genetic or acquired diseases, with varying severity
What are the symptoms of dehydrated skin?
Dehydrated skin is dull and lackluster. It is rough to the touch and streaked with dehydration lines. It is weak and lacks suppleness.
How does the skin get dehydrated?
Two causes :
- - Lack in water with less than 10% water in the upper skin layer (stratum corneum).
- - Alteration of the barrier function
How does the skin get dry?
Aside from skin disorders, two types of factors are responsible for dry skin:
• External factors :
- Climatic: Wind, cold, too much sun, lack of moisture in the air (air conditioner, heat)
- Chemical: Harsh cleansers, topical medical treatments, ill-suited cosmetics
- Mechanical: Shaving and hair removal.
• Internal factors :
- Physiological: Skin aging
- Pathological: Skin diseases that alter the skin barrier function.
Does dry skin lack water?
Yes, although it is not the only issue: You cannot rehydrate the skin’s superficial layer by just drinking water or wetting the skin. Lipids (fats) are also necessary for the moisture to stick.
Does the sun dry the skin?
Yes, it is one of the causes of dry skin. Sun exposure is an aggression (burn). The skin reacts by making pigments (the tan) and getting thicker. The dryness is transitory, caused by an increase in water loss.