Skin barrier and transepidermal water loss
One of the most important roles of the stratum corneum is to limit water loss by evaporation and to act as skin barrier against the penetration of agents from the external environment.

With age, the epidermis becomes thinner and dryer and it weakens the skin barrier. In addition, chronic dermatitis, atopic skin, psoriasis, xerosis or ichthyosis can lead to an increase in evaporation due to skin alteration.

The measurement of water evaporation from the skin surface is carried out mainly through the evaluation of transepidermal water loss (TEWL), a non-invasive method. The lower the TEWL value, the better skin condition.

Cosmetics can improve the skin barrier that has been damaged by external aggressions such as solar radiation, cold environments or pollution and products that have the ability to reduce the skin barrier recovery time ... ...