Abstract
Psoriatic arthritis (PsA), a chronic inflammatory arthritis, affects about 10 % of patients with psoriasis with higher prevalence seen in patients with more extensive skin disease. Early identification of PsA may result in improved outcomes. While it remains unclear which patients with psoriasis will develop PsA, several studies have identified potential risk factors for PsA among patients with psoriasis. This review examines the basic epidemiologic principles of identifying risk factors and reviews the evidence to date about risk factors for PsA among patients with psoriasis.