What is the importance of hydrating one's skin in the case of vitiligo?

Affecting between 0.5 and 2% of the global population, vitiligo is an acquired autoimmune dermatosis, with an underlying genetic susceptibility, characterised by the loss of melanocytes and, consequently, reduced melanin pigmentation. This loss is notably due to structural abnormalities of keratinocytes at the level of the white macules. Indeed, a dysfunction of the PI3K/AKT pathway, essential for the differentiation and survival of keratinocytes, has been observed in individuals with vitiligo. This dysfunction is notably correlated with a low quantity of E-cadherins in the skin, proteins that allow the cells of the epidermis to adhere to each other.

Furthermore, studies have shown a reduced presence of aquaporin-3 in the skin of individuals affected by vitiligo. This is a transmembrane protein involved in skin hydration. Indeed, aquaporin-3 plays a significant role in membrane permeability, and thus in the control of water exchanges between the interior and exterior of cells. It therefore seems possible that the low presence of aquaporin-3 in individuals affected by vitiligo could be the cause of reduced intrinsic skin hydration.

However, to date, there are very few studies on this subject. One of them, conducted in 2015, examined the various biophysical parameters of the skin of two individuals: one person not suffering from any skin disease and having a normal skin type, and another suffering from vitiligo. Corneometric tests, which measure the degree of skin hydration, and measurements of transepidermal water loss (TEWL) were carried out. The results obtained are compiled in the table below and seem to show a certain skin dryness in the skin affected by vitiligo. However, as the study only included two individuals, it is very difficult to draw solid conclusions. More research, involving large population panels, is still needed.

Although vitiligo is not directly associated with skin dryness like the eczema, some evidence suggests that it may be accompanied by a certain degree of skin dehydration.

Even though the link between skin hydration and vitiligo has not been formally established, it is reasonable to question whether individuals affected by this skin condition should adapt their skincare routine by using richer products. However, in the absence of scientific evidence at present, it is generally advised for everyone to listen to their own feelings in order to adapt their habits. The key lies in a routine that is simple and effective : a gentle cleanser to rid the skin of impurities at the end of the day, followed by a moisturising cream suitable for one's skin type, to be applied morning and evening. The use of a sunscreen every morning is also very important, especially for people with vitiligo, as the depigmented areas are more vulnerable to UV rays.

For individuals who experience tightness or persistent discomfort, it may be beneficial to supplement the routine with additional treatments, such as a hydrating serum to boost skin hydration or a soothing lotion, allowing for a comfortable sensation to be maintained throughout the day or night. These steps are not mandatory but can provide real benefits, depending on the individual needs of each skin type, whether it exhibits vitiligo or not.

• KIM N. H. & al. Reduced Aquaporin-3 Expression and Survival of Keratinocytes in the Depigmented Epidermis of Vitiligo. Journal of Investigative Dermatology (2010).

• THORKAR U. & al. Non invasive measurement of skin biophysical parameters in normal, psoriasis, vitiligo affected skin. International Conference on Industrial Instrumentation and Control (ICIC) (2015).

• BORRADORI L. & al. Dermatologie et infections sexuellement transmissibles. Elsevier Masson (2017).

• EZZEDINE K. & al. Vitiligo: A Review. Dermatology (2020).

• KOSHI S. & al. Vitiligo: A Narrative Review. Cureus (2022).