Defining the Role of the Skin Microbiome in Immune-related Adverse Events

The skin microbiome has been implicated in several cutaneous autoimmune pathologies such as psoriasis and atopic dermatitis. However, its role in vitiligo and vitiligo lesions occuring in patients receiving anti-PD-1 for metastatic melanoma

Inclusion Criteria: * Adult patients diagnosed with Vitiligo according to usual criteria. * Adult patients with metastatic melanoma, under anti-PD-1 who developed vitiligo * Adult patients with metastatic melanoma who did not develop Immune related adverse events under anti-PD-1 * Adult patients with metastatic melanoma who developed vitiligo under anti-PD-1 and discontinued the treatment * Free, informed by the participant and the investigator (at the latest on the day of inclusion and before any examination required by the research). Exclusion Criteria: * Patients under 18 years old. * No treatment for vitiligo in the past 4 weeks * Patients under legal protection or unable to express their consent. * Patients not affiliated to a health insurance system. * Patients deprived of liberty by judiciary or administrative decision or hospitalized without consent or admitted in a sanitary or social institution for another reason than research.