Diagnosis of subclinical psoriatic arthritis in patients with psoriasis using CASPAR criteria: a sonographic study

Abstract

Abstract Background We aimed at screening for subclinical psoriatic arthritis (PsA) among psoriatic patients without musculoskeletal complaints using ultrasonography of the lower limbs and finding the best predictor for its development. Results Subclinical inflammatory articular affection was found by ultrasound in 33 patients, among whom 26 had psoriatic nail affection. According to CASPAR criteria, those 26 patients could be diagnosed as PsA (subclinical). The only statistically significant difference between psoriatic patients with PsA and those without was the mean quadriceps tendon thickness as well as the presence of enthesophytes and bilateral quadriceps thickening. The best and only predictor for subclinical PsA was the presence of enthesophytes. Conclusion Ultrasound was more sensitive than clinical examination in detecting subclinical psoriatic arthritis which is highly prevalent in patients with psoriasis even in the absence of manifest arthritic complaints. The best and only predictor for subclinical PsA was the presence of enthesophytes.