Hyaluronic Acid's Effect on Psoriasis?

A dermatosis still relatively unknown to the general public, psoriasis manifests itself through excessive cellular renewal and an accumulation of epidermal cells, leading to a local inflammation. This disease is often caused by a combination of genetic and environmental factors. Another key element in the pathogenesis of psoriasis: an immune dysfunction. Indeed, people prone to psoriasis have an abnormal number of T lymphocytes in their epidermis, producing inflammation mediators (cytokines IL-17, IL-22, TNF-alpha...). These stimulate the proliferation of keratinocytes, accelerating cellular renewal from three weeks to three days. The result is an accumulation of keratinocytes, increasing the thickness of the horny layer: this is referred to as hyperkeratosis.

When suffering from psoriasis, it is crucial to maintain good skin hydration. Dryness is indeed a worsening factor, as several studies have shown that the skin's protective barrier function decreases and transepidermal water loss increases in psoriatic lesions. The hyaluronic acid, a natural moisturizer found in the skin, can address this issue. By attracting and retaining water molecules, this hydrophilic sugar limits skin dehydration and contributes to protect and maintain the epidermal barrier. However, it should be noted that not all types of hyaluronic acid act in the same way: high molecular weight hyaluronic acid remains on the surface of the stratum corneum and creates a protective film that prevents water from evaporating, while low molecular weight hyaluronic acid penetrates deeper into the epidermis where, in addition to its hydrating effects, it aids in cell regeneration and cohesion.

Furthermore, hyaluronic acid possesses intriguing anti-inflammatory properties in the case of psoriasis, which, let's remember, is an inflammatory dermatosis. This active ingredient indeed has a strong affinity for the CD44 receptor, allowing it to inhibit the release of pro-inflammatory cytokines, as well as the synthesis of matrix metalloproteinases (MMP) and prostaglandin E2 (PGE2), inflammatory molecules that contribute to exacerbating psoriatic lesions. Studies in vitro conducted with human keratinocytes have also shown that cells treated with hyaluronic acid produced less interleukin-8 and tumor necrosis factor (TNF-α), other agents of inflammation.

Finally, there is a clinical trial conducted today with 10 patients suffering from psoriatic lesions that has focused on the effects of hyaluronic acid on this condition. These individuals applied for one week patches of 26 x 26 mm with hyaluronic acid micro-needles. This non-invasive and painless technology enhances the delivery of hyaluronic acid and improves its penetration. Indeed, the micro-needle patches facilitate the absorption of active ingredients by the skin by creating numerous micro-channels in the stratum corneum. After one week, a complete resolution of the lesions was observed in two patients. Eight out of ten people considered themselves "satisfied" or "very satisfied" with the results. It should also be noted that no adverse effects were observed.

Key Takeaway : Even though more studies are needed, there are encouraging evidence regarding the effect of hyaluronic acid on psoriasis. However, this active ingredient cannot replace dermatological treatment.