[Immunology in clinical practice. VII. Psoriasis].

A new hypothesis of the pathogenesis of psoriasis holds that psoriasis is an epidermal hyperproliferative disorder resulting from abnormal interaction between T cells and basal layer stem cell keratinocytes. New therapies aimed at reducing T cell activity are most successful, as exemplified by the efficacy of systemic cyclosporine in severe cases of psoriasis. New developments in immunogenetics and immunodermatology are anticipated and it is expected that they will fully explain the chain of pathological events.