Is exposure to dust mites a trigger for vitiligo?

Invisible to the naked eye, mites belong to the arthropod family. They live on average for three months and thrive in warm and humid environments, ideally at a temperature of 77-86°F. This is why these microorganisms are primarily found in bedding, household linens, upholstered furniture, and carpeting. Contrary to popular belief, they can proliferate even in a clean house. While they are mainly associated with allergic problems, mites are also suspected of contributing to the development of vitiligo, an autoimmune dermatosis that manifests as the appearance of white spots on the skin. This is at least what a study recently published by researchers from INSERM suggests.

As a reminder, vitiligo is characterized by a loss of melanocytes, the cells responsible for skin pigmentation. This phenomenon, maintained by the immune system, occurs particularly through the destruction of E-cadherins, proteins that allow the cells of the epidermis to adhere to each other. However, several previously conducted studies have shown that mites produce proteases, enzymes that break down the peptide bonds of proteins. The question that arises is: do mites produce a protease that destroys E-cadherins?

To answer this question and better understand the role of mites in the onset of vitiligo, researchers used samples of epidermis taken from patients with vitiligo and from unaffected volunteers. They then exposed these samples to mites and observed that this contact triggered the secretion of chemokines and pro-inflammatory cytokines, as well as an increase in the concentration of proteases, with dose-dependent responses: the higher the quantity of mites used for the experiment, the stronger the concentrations of cytokines and proteases. Furthermore, they confirmed that one of the proteases released by the mites, Der p1, is responsible for the destruction of E-cadherins in the epidermis and the detachment of melanocytes.

These various phenomena, observed across all samples, were approximately a hundred times more significant in those derived from patients suffering from vitiligo. This led researchers to suspect a heightened susceptibility to mites in certain skin types, with more fragile cellular junctions at the epidermis level and a more reactive immune system. However, some areas of uncertainty remain: is exposure to mites a true triggering factor for vitiligo, or do mite allergies simply represent a common comorbidity? To answer these questions, further research is still needed, as the aforementioned study is currently the only one conducted on this topic.