Classification criteria can be used to homogenize patients and are valuable for scientific communication and clinical studies. The diagnosis of PsA is clinical, based on anamnesis, physical examination and imaging tests. Prevalence of psoriatic arthritis in a large cohort of Brazilian patients with psoriasis. , 3 3 Ranza R, Carneiro S, Qureshi AA, et al. Prevalence of psoriatic arthritis in patients with psoriasis: a systematic review and meta-analysis of observational and clinical studies. It is estimated that one in 3 or 4 patients with Pso will also have PsA [ 2 2 Alinaghi F, Calov M, Kristensen LE, et al. Prevalence and incidence of psoriatic arthritis: a systematic review and meta-analysis.
A metaanalysis of 28 studies regarding the frequency of PsA in the general population of several countries found an incidence of 83 cases per 100.000 person-years and an estimated prevalence of 133 cases per 100.000 people [ 1 1 Scotti L, Franchi M, Marchesoni A, Corrao G. Psoriatic arthritis (PsA) is defined as chronic inflammatory arthropathy associated with psoriasis (PsO), with an equal distribution between men and women.
