The epidemiology of psoriatic arthritis: A literature review.

Psoriatic arthritis (PsA) is a chronic, progressive musculoskeletal disease that affects 0.1%-1% of the general population and ~20% of patients with psoriasis. Significant differences exist in epidemiological estimates between studies, likely related to methodological and geographic differences. While most studies show an increase in prevalence over recent years, the underdiagnosis of PsA persists. Studies suggest that a complex interaction of multiple factors is involved in the development of PsA in patients with psoriasis and a single factor may not be able to effectively define at-risk patients with PsA. Modification of some risk factors such as weight loss may help in the prevention of the disease and improved outcomes.