Psoriasis: The Role of Skin Hydration

The psoriasis is a skin disease that is recognized by the red and scaly patches that cover specific parts of the body. These can be a source of itching and irritation, their intensity varying from one individual to another. They appear following skin inflammation caused by a failure of the immune system. T lymphocytes produce inflammatory molecules (cytokines IL-17, IL-22, TNF-alpha, etc.). These stimulate the proliferation of keratinocytes. The renewal period of these cells, normally three weeks, then becomes three days. This results in an accumulation of immature keratinocytes on the skin surface, increasing the thickness of the outer layer (hyperkeratosis).

One of the exacerbating factors of psoriasis is skin dryness. Indeed, hydration and the water content of the stratum corneum are key factors that allow the skin to perform its protective barrier function. Numerous studies have shown that the protective barrier function of the skin decreases and that transepidermal water loss increases in psoriatic lesions.

To alleviate the symptoms of psoriasis, it is crucial to maintain a constant level of skin hydration. The application of moisturizing treatments helps to strengthen the protective barrier by maintaining the hydrolipidic film and reducing the risk of skin dehydration . This makes the epidermis more resistant to external aggressions and reduces the Koebner phenomenon. This phenomenon refers to the appearance of new lesions from an already existing dermatosis, in this case psoriasis, on a previously healthy area of skin.

Moisturizing products are not a standalone treatment, but they are essential as an adjunct therapy. In addition to hydrating, these treatments also help soothe the skin from irritations caused by psoriasis.