A simple tool could help dermatologists identify patients truly at risk of psoriatic arthritis.
Canadian researchers have created a tool to help predict the risk of progression to psoriatic arthritis in patients with psoriasis.
It’s known that people with psoriasis are at increased risk of developing PsA, and individual risk factors have been identified with varying levels of evidence. However, the researchers noted, there was currently no unifying prediction tool.
Investigators, led by Dr Lihi Eder of the Women’s College Hospital and University of Toronto, set out to create such a tool: the Psoriatic Arthritis Risk Estimation Tool (PRESTO).
“A simple, scalable tool that identifies patients with psoriasis who are at high risk for developing PsA will be an important step towards improving early detection enabling opportunities for early interventions, which may halt progression from psoriasis to PsA,” they wrote in Arthritis & Rheumatology.
The study included 635 patients from the Toronto Psoriasis Cohort who were free of clinical inflammatory arthritis at the time of enrolment.
The authors identified potential risk factors to predict progression from psoriasis to psoriatic arthritis.
Obesity, extensive psoriasis and psoriatic nail lesions had the most consistent evidence, while less consistent risk factors included location of psoriasis, history of uveitis, comorbidities (such as thyroid disease and depression) and recent physical trauma. Other symptoms known to predict PsA in psoriasis patients include pain, fatigue and stiffness.
Patients were assessed on 29 variables – including those identified above, plus other potential candidates – at baseline and at annual follow ups. At the one-year follow up, 51 patients had developed PsA, with 71 having developed PsA at the five-year follow up.
The variables that predicted increased risk of PsA at one year were male sex, family history of psoriasis, morning back stiffness, nail pitting, stiffness level, use of biologic systemic medications and pain. Age and patient global health were associated with a reduced risk. All these variables were included in the one-year risk model.
Variables selected for the five-year prediction model were presence of morning joint stiffness, PASI, psoriatic nail lesions, Functional Assessment of Chronic Illness Therapy Fatigue scale, use of non-biologic systemic medications/phototherapy and pain.
The PRESTO tool is available online.
“PRESTO has demonstrated good model fit metrics including discrimination and calibration and its threshold could be adjusted depending on the purpose of its use (e.g. higher sensitivity for screening, higher specificity for enrichment with high-risk patients for interventional studies),” wrote the authors.
“Accurate estimation of PsA risk using PRESTO among patients with psoriasis has important potential applications in clinical care, such as promoting early diagnosis and interventions to prevent progression from psoriasis to PsA.”
