Psoriatic arthritis onset in psoriatic patients receiving UV phototherapy in Italy

Psoriasis is a chronic, recurrent, and immune-mediated inflammatory disease that affects 2-3% of the world population. A substantial proportion of patients with psoriasis, approximately 40 %, develop a form of inflammatory arthritis known as psoriatic arthritis (PsA), the arthritis follows the development of psoriasis, and it will develop simultaneously or possibly before the appearance of skin lesions. The presence of PsA indicates a need for more active intervention rather than purely topical therapies or UV-based therapies. The aim of this multicenter, retrospective, epidemiological study was to estimate the incidence of PsA in psoriatic patients receiving UV treatment as monotherapy