It is a study of translational research with mechanistically objectives and including biological samples of patients with chronic inflammatory disorders

This study was a single-center prospective study to collect blood and skin tissue at the time of consultation with a patient with non-segmental vitiligo, psoriasis, atopic dermatitis or alopecia areata, in order to better understand and compare blood and skin immune response in chronic inflammatory skin disorders: psoriasis, alopecia areata, atopic dermatitis and vitiligo.

Inclusion Criteria:

• Patients aged 18 to 75 years;
• Patients with non-segmental vitiligo;
• Patients with plaque psoriasis;
• Patients with atopic dermatitis;
• Patients with alopecia areata sclerosis;
• written consent, free, informed and signed by the patient and the investigator (before any examination required by the study);
• Subject affiliated or beneficiary of a social security system.

Exclusion Criteria:

• Patients with segmental vitiligo
• Patients under local treatment (topical corticosteroid-Calcineurin inhibitor) for less than two weeks.
• Patients on therapy, systemic treatments: acitretin, methotrexate, cyclosporine, Apremilast, infliximab, adalimumab, etanercept, ustekinumab, secukinumab, ixekizumab, dupilumab) for less than 4 weeks.
• Pregnant or breastfeeding women
• Patient (e) under guardianship
• Patient (e) Non-affiliated (e) a social protection

450 patients (300 patients with vitiligo, 50 psoriasis patients, 50 patients with atopic dermatitis, 50 patients with alopecia areata)