2323: Short-term predictive factors for the development of psoriatic arthritis in patients with psoriasis: findings from a joint consultation between Rheumatology and Dermatology

Background/Purpose: Psoriatic Arthritis (PsA) is a chronic rheumatic disease that develops in up to one-third of patients with psoriasis. Identifying predictive factors for PsA in patients with psoriasis referred to rheumatology clinics can facilitate early detection and improve disease outcomes.

Objectives: To identify predictive factors for the development of psoriatic arthritis (PsA) after 12 months of follow-up in patients with a diagnosis of psoriasis referred to a rheumatology clinic.

Methods: An observational, analytical, retrospective study was conducted on 109 patients with psoriasis referred to rheumatology from the dermatology department. Demographic, clinical and analytical data were collected at the first visit to the rheumatology clinic and after 12 months of follow-up. Patients were classified as having PsA yes/no at the 12-month visit based on the rheumatologist’s opinion. Baseline characteristics potentially predictive of a PsA diagnosis were analysed using chi-squared and Student's t-tests. Finally, multivariate logistic regression was performed to evaluate the predictive factors independently associated with the development of PsA.

Results: Among the 109 patients evaluated, 54.1% were female and the mean age was 50.8 (12.1) years. A total of 52.9% had plaque psoriasis, and 55.6% had nail involvement. The most frequent reasons for referral were arthralgias (66.1%) and arthritis (16.5%). Additionally, 25% of the referred patients were already receiving biologic treatment prescribed by the dermatologist. A total of 41 patients (37.6%) were diagnosed with PsA after 12 months of follow-up.

Univariate analysis (table 1) showed that factors significantly associated with the development of PsA were: male gender (54.0% vs. 23.7%), arthritis as the reason for referral (61.0% vs. 29.2%), plaque psoriasis (54.1% vs. 14.3%), nail involvement (46.7% vs. 26.5%), elevated CRP (mean 12.0 vs. 5.3 mg/L) and being on biologic treatment (55.6% vs. 31.7%).

Finally, multivariate logistic regression (Table 1) demonstrated that male gender (OR 3.6, 95% CI 1.3 - 9.5) and plaque psoriasis (OR 6.0, 95% CI 2.0 - 7.2) were the most important predictors for the development of PsA. Conversely, patients referred for symptoms other than arthralgias or arthritis had a lower risk of developing PsA (OR 0.2, 95%CI 0.1 - 0.7).

Conclusion: This study in routine clinical practice suggests that male gender, the presence of plaque psoriasis and referral for arthritis or arthralgia are independently associated with the development of PsA. Further long-term prospective studies are required to confirm these findings.