The prevalence of psoriatic arthritis in people with psoriasis

Abstract

Objective. To determine the prevalence of psoriatic arthritis (PsA) using the ClASsification criteria for Psoriatic ARthritis (CASPAR) for classification. Methods. People with psoriasis were identified from the computerized morbidity indices of 2 large UK general practices, total population 22,500. Questionnaires were mailed to all 633 patients thus identified. Of the respondents, a 50% sample was assessed clinically and a proportion had blood samples and radiographs taken. Patients labeled as having psoriasis were also cross-referenced with a local secondary care morbidity index for PsA and rheumatoid arthritis. Figures for the prevalence of PsA were estimated from these data. Results. One hundred sixty-eight questionnaires were returned (response rate 27%) and 93 people (55% of questionnaire respondents) were examined. Of these 93 people, 12 (4 of whom were cross-referenced to the hospital database) were thought to have PsA clinically, all fulfilling the CASPAR criteria for PsA. Six of the 93 examined patients did not have psoriasis or a family history of psoriasis and had no historical features or clinical signs of psoriasis on interview and examination. Extrapolating from the data of those people actually examined, the estimated (corrected) prevalence was 13.8% (95% confidence interval 7.1-24.1%). Conclusion. The estimated prevalence of PsA in this population, using the CASPAR criteria, was 13.8%. Misclassification of psoriasis and arthritis, and response bias, indicate that this is probably an overestimate.

Psoriatic Arthritis and Burden of Disease: Patient Perspectives from the Population-Based Multinational Assessment of Psoriasis and Psoriatic Arthritis (MAPP) Survey

“…PsA was reported in 21% of the overall MAPP patient population, which is generally consistent with published prevalence estimates [4,12,16,25,28].…”

“…The clinical presentation of PsA varies. It occurs in approximately 30% of patients with psoriasis [4,12,16,25,28] and typically follows the onset of psoriasis by approximately 8-10 years [12,22].…”

“…Nail involvement typically occurs more often and is more severe in patients with PsA than in those with psoriasis alone and may predict the development of PsA in patients with psoriasis [10,12,16,20,24,30,35].…”

Psoriatic arthritis: state of the art review

“…11 Generally, laboratory tests are unhelpful: markers of systemic inflammation, such as the C-reactive protein or erythrocyte sedimentation rate, may be elevated in only 50% of cases and low titre rheumatoid factor and anti-cyclic citrullinated peptide may be found in up to 10% of cases. 4 Current National Institute for Health and Care Excellence guidance for the management of psoriasis suggests that the Psoriasis Epidemiology Screening Tool patient-completed screening questionnaire 12 ( www.bad.org. uk/healthcare-professionals/forms-downloads ) should be used annually to identify PsA.…”

IL12/IL23 Inhibition in the Treatment of Psoriatic Arthritis

“…Psoriasis is a relatively common disease, affecting about 2 % of the general population; up to 25 % of these patients develop PsA about 10 years after the development of skin disease [1]. Increasing knowledge about the pathophysiology of psoriasis and PsA has revealed that the diverse disease manifestations observed in these disorders may share common immunologic and inflammatory pathways.…”