Non-contagious but difficult to manage, eczema is an inflammatory skin condition that causes red patches accompanied by intense itching and tends to flare up periodically. Depending on its type, it can be genetic (atopic eczema) or acquired (contact eczema). In the former case, eczema is characterized by a fragile skin barrier, often due to a mutation in genes coding for structural proteins of the stratum corneum. The hydrolipidic film of atopic skin is also altered. Contact dermatitis, on the other hand, occurs when the skin comes into contact with an allergen and disappears after its removal.
Contrary to dermocorticoids often prescribed by dermatologists, the evidence of squalane's effectiveness on eczema is limited.
Thanks to its structure, which is similar to that of sebum, squalane has a strong affinity with the skin. Through biomimicry, this lipid is able to integrate into the protective hydrolipidic film present on the skin's surface and strengthen it. Non-greasy, squalane easily penetrates the epidermis, thus providing the skin barrier with the lipids it needs. This property of squalane could potentially be interesting for people suffering from eczema. Indeed, this ingredient could possibly alleviate the characteristic skin dryness of this dermatosis, thereby helping to reduce the sensations of itching associated with eczema.
However, to date, the effect of pure squalane in cases of eczema has not been studied. Only a few studies have shown that moisturizing creams formulated with squalane and other humectant, restructuring, and soothing agents, could help to alleviate the redness and itching of eczematous skin. The results of two of these are presented in the table below. These clinical trials, however, do not allow us to conclude that squalane is truly a beneficial ally in cases of eczema. Indeed, the cosmetic formulations studied were made with many other ingredients (glycerin, ceramides, allantoin, bisabolol...): it is therefore not certain that squalane contributed to the reduction of symptoms.
Furthermore, the only scientifically proven property of squalane that could be relevant for eczema is its moisturizing action. Indeed, no study has proven that squalane can reduce skin inflammation, unlike squalene from which it is derived. In vitro, it has been shown that squalene exerts an immunomodulatory action on pro-inflammatory M1 macrophages of cells involved in skin irritation. Squalene also triggers an increase in the synthesis of anti-inflammatory cytokines such as IL-10, IL-13, and IL-4, and a decrease in pro-inflammatory signals, such as TNF-α and NF-kB. While squalene has soothing and healing effects beneficial for eczematous skin, there is currently no scientific evidence that this is the case for squalane.
Today, it is impossible to definitively state that squalane can help reduce eczema. We can only hypothesize that this active ingredient might potentially assist in maintaining skin hydration, thereby spacing out flare-ups.