[Psoriasis: pathogenesis and treatment].

Psoriasis is a T-cell mediated disease. Its pathogenesis is linked to the activation of T-cells by antigen-presenting cells and secretion of cytokines able to modulate keratinocyte proliferation and differentiation. Antigens involved in psoriasis triggering are unidentified. Several new biological immunomodulatory treatments able to block T-cell activation and epidermal cells modifications are currently investigated.