Classification Criteria Help ID Polymyalgia Rheumatica

(HealthDay News) – Provisional classification criteria have been established to discriminate polymyalgia rheumatica (PMR) from conditions which mimic PMR.

To develop European League Against Rheumatism/American College of Rheumatology classification criteria for PMR, Bhaskar Dasgupta, MD, of Southend University Hospital in Westcliff-on-Sea, UK, and associates evaluated candidate criteria in a six-month prospective cohort study of 125 patients with new-onset disease and 169 controls with conditions mimicking PMR.

The researchers developed a scoring algorithm on the basis of four factors: more than 45 minutes of morning stiffness; hip pain/limited range of motion; absence of rheumatoid factor and/or anti-citrullinated protein antibody; and absence of peripheral joint pain. A score of >4 discriminated PMR cases from controls with 68% sensitivity and 78% specificity. Shoulder conditions could be discriminated with greater specificity (88%), while rheumatoid arthritis was discriminated with lower specificity (65%). A score of >5 increased sensitivity to 66% and specificity to 81%, on addition of ultrasound.

“According to these provisional classification criteria, patients ≥50 years old presenting with bilateral shoulder pain, not better explained by an alternative pathology, can be classified as having PMR in the presence of morning stiffness >45 minutes, elevated C-reactive protein and/or erythrocyte sedimentation rate, and new hip pain,” the authors write.

Several authors disclosed financial ties to the pharmaceutical industry.

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