The study of psoriasis (PS) is a pressing issue due to the high prevalence of the disease, increased mortality of patients, formation of severe and treatment-resistant forms, lack of effectiveness of the existing methods of pathogenetic and symptomatic treatment. Early prediction of the formation of severe psoriasis prevents progression of the disease and involvement of various organs and systems into the pathologic process, such as the musculoskeletal system with formation of psoriatic arthritis (PsA). Objective. The study is aimed at assessing the clinical and anamnestic features of psoriasis and psoriatic arthritis and determining markers having prognostic value for formation of severe forms of the disease. Material and methods. The study included 97 patients with advanced stage of PS vulgaris. The patients were divided into two groups. Group 1 consisted of PS patients (n=49) and group 2 consisted of PsA patients (n=48). The control group consisted of apparently healthy blood donors (n=45), matched by sex and age. The patients were surveyed using inquiry and questionnaires, physical examination, and anthropometry with calculation of body mass index (BMI). Results. There are the following risk factors for PsA: female gender, age over 50 years, the duration of the disease more than 10 years, continuously relapsing skin process, the lack of seasonality of exacerbations of the disease, high PASI index, hospital treatment 1—3 times a year lasting more than 14 bed-days, BMI ≥25 kg/cm2, no effect of stress and nutritional factors on the worsening of the skin, pruritus and Koebner phenomenon, nail and scalp PS, concomitant involvement of the hepatobiliary system (GBS), for example, the history of gastrointestinal tract diseases, dyspeptic complaints, relation between the exacerbation of the skin disease and relapsed of GBS diseases.