Salivary Gland Sonography in Patients with Primary Fibromyalgia—A Pilot Study

Primary Sjogren's syndrome (pSS) is often concomitant with fibromyalgia (FM). Salivary gland sonography aids in the diagnosis of pSS. We aimed to discover, in primary FM patients, the presence of pSS in undiagnosed patients through salivary gland sonography. We prospectively recruited 42 primary FM patients. FM symptoms were evaluated based on the revised Fibromyalgia Impact Questionnaire (FIQR). Salivary gland sonography was performed. Patients with positive findings underwent salivary gland biopsy. Comparisons were undertaken using the Mann-Whitney U tests and Chi-squared test. In primary FM patients, the prevalence of dry eye was 83%, and dry mouth was 90%. The salivary gland sonographic score did not differ between patients with and without dry eye/mouth. One patient with a positive finding at salivary gland sonography had a positive result of salivary gland biopsy. In the other four patients who received salivary gland biopsy, despite negative findings in salivary gland sonography, only one had a positive result of salivary gland biopsy. To be noted, scores evaluated by salivary gland sonography were negatively associated with levels of pain (rho = -0.360, <i>p</i>= 0.023) and levels of sleep quality (rho = -0.447, <i>p</i> = 0.004). Our pilot study demonstrated the potential of salivary gland biopsy in detecting undiagnosed pSS in primary FM patients.