The paper presents epidemiology, pathogenesis, environmental triggers and types of psoriasis depending on the first psoriatic lesions. The immunological system by cytokines which source are keratinocytes, plays the important role in psoriatic course. The core feature of the disease is increased number of mitotic figures in the basal lamina of the epidermis and accelerated abnormal maturation of keratinocytes. Keratinocyte is the main cell in psoriasis and source of many cytokines. Proinflammatory cytokines and cytokines with inhibitory effect for psoriasis have been described. The authors show results with use of method of blocking cytokines operation (against interleukin TNF alpha) and using of interleukin 4 and interleukin 10 in therapy of psoriasis.