According to a recent report published in the Journal of the European Academy of Dermatology and Venereology, Etienne Audureau, MD, PhD, and colleagues have developed an easy-to-implement screening tool for psoriatic arthritis (PsA) in patients with psoriasis. This rating scale, Psoriatic arthritis UnclutteRed screening Evaluation-4 (PURE-4), may help facilitate timely referrals to rheumatologists for those with PsA.
Investigators conducted a literature review, identifying 23 possible items for inclusion in the rating scale. These items included pain at various locations and inflammatory signs of PsA.
Patients from St. Joseph Hospital, Paris, France, who had been medically diagnosed with psoriasis were recruited by dermatologists for completion of the questionnaire.
Diagnosis of PsA was made by rheumatologists using CASPAR criteria, and univariate associations between the items and PsA diagnosis were analyzed. Multivariate regression models were performed, and discrimination was assessed using sensitivity, specificity, and area under receiver operator curve. Bootstrapping techniques validated the final model.
The clinical sample included 137 patients (median age 43 years, 59.6% men), 21 (15.3%) of whom had diagnoses of PsA. Univariate analysis revealed 15 of the 23 items that were significantly associated with diagnosis of PsA. Final logistic regression modeling resulted in 4 items: evocative signs of dactylitis, inflammatory heel pain, bilateral buttock pain, and peripheral joint pain with swelling in patients age >50 years.
The number of positive items was summed to a total score of 0 to 4 points. At ≥1/4 points, this score demonstrated excellent discriminative ability (area under the curve=87.6%; sensitivity 85.7% and specificity 83.6%). Bootstrapped internal validation did not show overfitting.
“These findings demonstrate the good diagnostic properties of a new screening scale using only 4 easy-to-collect items,” the authors commented. Although the study may be limited by a relatively low sample size and absence of external validation studies, the screening scale “may prove useful in outpatient dermatology clinics for triage of psoriasis patients requiring further assessment by the rheumatologist.”
Disclosures: Funding for the study was provided by MSD France. Several authors declare affiliations with the pharmaceutical industry.
Audureau E, Roux F, Lons Danic D, et al. Psoriatic arthritis screening by the dermatologist: development and first validation of the ‘PURE-4 scale’ [published online March 9, 2018]. J Eur Acad Dermatol Venereol. doi:10.1111/jdv.14861