Psoriasis is one of the most common skin diseases. It is an inflammatory dermatosis characterised by excessive keratinocyte proliferation. Genetic, environmental and immunological factors play a role in the pathogenesis of ps oriasis. There are two clinical forms of skin psoriasis: ordinary and pustular psoriasis, as well as psoriatic arthritis. Psoriasis is a chronic disease characterised by a variable frequency of relapses and length of remission. Flare-ups are often caused by triggers such as stress, infections or alcohol. The treatment of psoriasis depends on the clinical form and severity of the lesions, and is most often a combination treatment combining various forms of external treatment with phototherapy or systemic preparations.