Psoratitis arthropathy (arthropathic psoriasis, psoriatic osteoarthritis, psoriasis of the musculoskeletal system, interstitial undifferentiated arthritis, atypical polyarthritis) is a special form of psoriasis of a non-infectious nature, in which damage occurs not only to the skin and mucous membranes, but also to joints without an inflammatory reaction and with subsequent progressive erosive syndrome due to resorption of articular surfaces. Arthropathic psoriasis mainly affects middle-aged women.