Psoriasis is a chronic papulosquamous skin disease, histologically characterized by
epidermal hyperproliferation and dermal infiltration of inflammatory cells. The majority of T
lymphocytes infiltrating dermis are CD4+ T lymphocytes secreting type 1 and type 17
cytokines. These cytokines are responsible for triggering keratinocyte proliferation as well as
chemokine secretion and subsequent migration of other inflammatory cells in the skin.
Contrarily, lymphocytes that accumulate in epidermis are mainly CD8+ T lymphocytes …