Dendritic cells (DC) paly a key role in the induction and chronicity of psoriasis by capturing the antigenes and activating the T cell repsonse. This activation requires their migration from the cutaneous sensitisation site to the lymph nodes. This migration requires an important intracellular metabolic activity, with a strong involvmenet of glucdic metabolism. This activity is linked with the systemic activity. This study aims to compare the migration and the phenotypic and metabolic caracteristics of blood and skin DCs in patients with or without psoriasis and with or without type 2 diabetes,

Inclusion Criteria:

• Patients of both sexes
• hospitalized in the Dermatology department of the CHU of Nice for moderate to severe psoriasis (defined by a PASI > or = 10)
• covered by a social security scheme after obtaining a free
• Clinical diagnosis of plaque psoriasis by a dermatologist with or without type 2 diabetes (defined by glycated hemoglobin >7%)
• For the control group: without psoriasis or other inflammatory dermatosis aged in the presence or not of type 2 diabetes (glycated hemoglobin >7%).
• free and informed consent

Exclusion Criteria:

• Minor or incapable or unwilling to consent freely or in an informed manner Pregnant or nursing woman.
• Patient in a period of exclusion from other biomedical research
• Patient with generalized chronic inflammatory disease or other inflammatory dermatosis
• Patients on general corticosteroid, immunomodulator or immunosuppressant therapy in the month prior to local inclusion or treatment with corticosteroid therapy in the 15 days prior to inclusion, on anti- treatmentIL-23 or anti IL12/23 for less than 3 months or under anti-IL-17 or anti-TNF treatment for less than 1 month.
• Contraindication to cutaneous biospsis (known hemostasis disorder, taking anticoagulants, allergy to xylocaine, history of cheloid scars, congenital immune deficiency)