Psoriatic arthritis (PsA) is a heterogeneous chronic inflammatory arthritis associated with psoriasis, which may manifest with different domains such as dactylitis, enthesitis, synovitis and spondylitis. The estimated prevalence of PsA in patients with psoriasis ranges widely between 6% and 42%. In most cases, PsA is preceded by skin involvement by an average time of 7–8 years. In the complex patho-mechanisms involved in the transition from psoriasis to PsA, the gut and skin have been proposed as the sites of immune activation triggering or contributing to the development of PsA. In such a transition, a subclinical phase has been identified, characterized by enthesopathy where soluble biomarkers and imaging findings but no clinical symptoms are detectable. Recent studies have provided some evidence that timely treated psoriasis may reduce the risk of developing PsA.