Ultrasound assessment of the entheses in primary Sjögren syndrome.

Although tendon pain is commonly reported in primary Sjögren syndrome (pSS), the underlying mechanism is unknown. The objective of this study was to determine whether tendon pain in pSS is related to involvement of the tendons and entheses. We performed a physical examination of 288 entheseal insertion sites in 16 patients with active pSS and 162 entheseal insertion sites in 9 healthy controls without symptoms or medications. Then ultrasound was used to assess entheseal and tendon sites of these patients (n = 208) and controls (n = 117). Ultrasound was performed in B mode first to detect structural damages, and in power Doppler mode to detect blood flow abnormalities. By physical examination, 9 (56%) of the 16 pSS patients had pain to palpation of fibromyalgia tender points, two of whom had more than 11 tender points. The number of positive points ranged from 2 to 18, with a mean of 8 ± 6.0. None of the healthy controls had positive tender points. None had structural or blood-flow abnormalities by ultrasound. To conclude, this study provides the first data on ultrasound findings in patients with active pSS. Although 56% of patients had clinical tender points, none had structural or blood-flow abnormalities by ultrasound, suggesting the absence of inflammation of the tendons and entheses in this disease.