Psoriatic arthritis and Cutaneous Psoriasis are polygenic inflammatory disorders with high burden on the quality of life of patients. Pathophysiology of those disease remain incompletely understood. Recent publications seem to demonstrate an implication of IL-1 family cytokines in the pathogenesis of both diseases. In the literature, results are discordant and focus mainly on cytokines levels in serum of patients. Moreover, few studies compare psoriatic arthritis patients with cutaneous psoriasis patients. We propose here to study cytokines profiles of patients with those conditions in sera, after ex-vivo stimulation of peripheral blood mononuclear cells, and in skin biopsies.