Sonographic Evaluation of Subclinical Enthesopathy in Patients of Chronic Plaque Psoriasis

BACKGROUND: Psoriasis is associated with spondyloarthropathy in 10%–30% of cases. Enthesitis is major feature of psoriatic arthritis. Ultrasonography can detect subclinical entheseal abnormalities in psoriasis patients. OBJECTIVES: To determine the prevalence of subclinical enthesopathy in psoriasis vulgaris using ultrasonography and evaluating its correlation with severity and duration of psoriasis. MATERIALS AND METHODS: This study included 50 patients of psoriasis vulgaris and 50 healthy controls. Sonographic evaluation of six sites bilaterally (proximal plantar fascia, distal Achilles tendon, distal and proximal patellar ligaments, distal quadriceps, and brachial triceps tendons) were done in each subject. All Ultrasonographic findings were identified according to MASEI (Madrid sonography enthesitis index). Enthesopathy scores of patients and controls were compared and receiver operating characteristic curve was used to determine cut off value of MASEI, above which ultrasound enthesitis of clinical significance could be diagnosed. RESULTS: 31 (62%) psoriasis patients had subclinical enthesopathy of clinical significance as compared to only 5 (10%) of controls. Mean MASEI score between psoriasis cases and control was statistically different, 12.72 ± 7.55 (Mean ± SD) and (5.14 ± 4.69), respectively (P value 0.000001).The receiver operating characteristic curve established an ultrasound score of >11 as the best cut-off to differentiate between subject with enthesopathy of clinical significance from those with enthesopathy of unknown significance. No statistically significant correlation was found between the degree of enthesopathy (MASEI score) and duration and severity of the psoriasis. CONCLUSION: Ultrasonography can effectively screen subclinical entheseal abnormalities in psoriasis patients.