Which soap should be used for dry and dehydrated skin?

Knowing your skin type is crucial for selecting appropriate skincare. Dry skin suffers from a lack of "oil" due to a deficiency in sebum, which then weakens the skin's barrier function. Indeed, sebum, the main component of the hydrolipidic film, helps protect the skin against external aggressions and limit water loss. However, this insufficient sebum production makes the skin vulnerable to external factors and therefore reacts quickly. Thus, if you have dry skin, you may experience redness, fine cracks (sometimes deeper fissures that can bleed), itching and flaking, rough rather than silky skin, and a feeling of tight skin.

Dehydrated skin is caused by a lack of water. Unlike dry skin, dehydrated skin is a skin condition that can affect all skin types, even oily skin. In the case of dehydration, the signs are not constant as they are for dry skin. Thus, the skin may appear less radiant, less supple, duller, rough, tight, and fine lines are more visible. This is explained by a water imbalance between the different layers of the skin. Indeed, the water lost on the skin's surface through evaporation is faster than the transfer between the dermis and the epidermis. This change is due to the impact of external factors (pollution, stress, climate variations, etc...) or those of endogenous origin (malfunction of the constitutive elements of the epidermis, permeabilization of the hydrolipidic film, etc...) on the skin.