[Fibromyalgia and Sjögren syndrome--clinical and methodological aspects]

The prevalence of fibromyalgia in primary (n = 18) or secondary (n = 20) Sjögren's syndrome was examined. In all patients with Sjögren's syndrome as well as in 31 fibromyalgia patients and 20 healthy individuals measurements of pressure pain threshold were done by palpation and dolorimetry. Widespread pain, functional complaints, as well as depression were determined by a questionnaire. The results show a high frequency of fibromyalgia in the group of patients with pSS (44%), 72% of pSS patients reported widespread pain. Only 5% of the sSS patients fulfilled the ACR criteria for fibromyalgia and 40% of this group reported on widespread pain. Dolorimetry measures at tender or control points revealed that the pressure pain threshold was significantly reduced in all patient groups with healthy controls. There were only small differences between the clinical groups. Within the different groups examined there was a close correlation between dolorimetric threshold at tender and control points. In contrast to self-estimated widespread pain the pressure pain threshold was not closely related to functional complaints in the patient groups. The prevalence of depression was increased in both pSS and FM patients, in contrast to the other groups. The results suggest to include Sjögren's syndrome into the differential diagnosis of FM. The dolorimetric results were interpreted as an argument against the actual tenderpoint concept. They support the view that patients with FM rather represent an arbitrary coincidence of widespread pain and elevated tenderness on pressure.