HealthDay News – Severe psoriasis, nail pitting, and the use of retinoids were identified as possible risk factors for development of psoriatic arthritis (PsA) among patients with psoriasis, according to a study published in the April issue of Arthritis & Rheumatology.
Lihi Eder, MD, PhD, from Toronto Western Hospital, and colleagues conducted a prospective cohort study involving psoriasis patients without a diagnosis of PsA. Information was collected regarding lifestyle, comorbidities, psoriasis activity, and medication use. Using an event per person-years analysis, the annual incidence of PsA was estimated.
Data were obtained from 464 patients who were followed for eight years. The researchers found that 51 patients developed PsA, with an annual incidence rate of 2.7 cases per 100 psoriasis patients. In multivariate analysis, severe psoriasis (relative risk [RR], 5.4), low level of education (university/college versus high school incomplete: RR, 0.22; high school graduate versus high school incomplete: RR, 0.30), and use of retinoid medications (RR, 3.4) correlated with the development of PsA.
Psoriatic nail pitting and uveitis correlated with development of PsA in multivariate models with time-dependent variables (RRs, 2.5 and 31.5, respectively).
Summary and Clinical Applicability
This study confirmed prior findings that psoriatic nail lesions and psoriasis severity were associated with increased risk of developing PsA in psoriasis patients. In addition to these risk factors, uveitis and low education levels were identified as possible predictive risk markers in this particular cohort.
Limitations and Disclosures
“Due to the study design, patients who developed PsA prior to or concurrent with the diagnosis of psoriasis were excluded.. Incident cases of PsA may be overrepresentative of a certain [HLA–C*06-associated] PsA”, the study authors concluded.
This study was funded by the Krembil Foundation and the Canadian Institutes of Health Research.
Eder L, Haddad A, Rosen CF, et al. The incidence and risk factors for psoriatic arthritis in patients with psoriasis – a prospective cohort study. Arthritis Rheumatol. 2015; [Epub ahead of print] March 28, 2016. DOI: 10.1002/art.39494