Psoriatic arthritis and gout (linked to hyperuricemia) are two rheumatisms well known to rheumatologists. There are epidemiological and physiopathological arguments in favor of a non-fortuitous link between these two rheumatisms, which to date has not been established. There is currently no recommendation to treat hyperuricaemia without an episode of gout attack. We hypothesize that there is a link between hyperuricemia and severity of rheumatism. This would ultimately modify the therapeutic management of hyperuricemic patients followed for psoriatic arthritis.

Inclusion criteria:

• Major subject (≥18 years old)
• Subject with a history of psoriatic arthritis objectified according to the CIM 10-1 coding for patients followed in hospitalization at the HUS and HCC
• Subject presenting psoriatic arthritis objectified during a consultation by an HCC rheumatologist
• Among these two populations, all subjects for whom at least one serum uric acid assay was available in the medical file
• Subject having not expressed, after being informed, opposition to the reuse of their data for research purposes

Exclusion criteria:

• Subject who expressed their opposition to participating in the study
• Subject who met the inclusion criteria but whose analysis of the medical file (anamnestic, clinical, biological and radiological data) led to a diagnostic reversal and therefore did not present with psoriatic arthritis
• Subject under guardianship or curatorship
• Subject under safeguard of justice

Major subject (≥18 years old), with a history of psoriatic arthritis objectified according to the CIM 10-1 coding for patients followed in hospitalization at the HUS and HCC and subject presenting psoriatic arthritis objectified during a consultation by an HCC rheumatologist