Screening for Primary Sjögren’s Disease in Patients with Burning Mouth Syndrome: Clinical, Serologic, and Sialometric Findings

Background and Objectives: Oral burning is the primary complaint in burning mouth syndrome (BMS), but it can also be an early manifestation of primary Sjögren’s disease (pSD). Because BMS is a diagnosis of exclusion, unrecognized pSD may remain undiagnosed and be treated only symptomatically. This study aimed to screen patients with BMS for pSD and to identify clinical, serologic, and sialometric findings that could guide targeted referrals. Materials and Methods: This cross-sectional study included 85 adults with chronic oral burning who met the International Classification of Orofacial Pain (ICOP) criteria for BMS after local and systemic causes were excluded. Patients were evaluated at the Department of Dental Medicine, University Hospital of Split, Croatia. The 2016 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria were used to identify pSD. Burning intensity (visual analogue scale, VAS), unstimulated (Qs) and stimulated (Qss) whole salivary flow rates, and hematologic, biochemical, and autoantibody findings were compared between patients with pSD and those with BMS alone. Results: pSD was identified in 5 patients (5.9%; 95% CI, 1.9–13.2%), all women older than 60 years. Patients with pSD were older than those with BMS alone (p = 0.049). Burning intensity did not differ between groups (p = 0.575). Both Qs (median: 0.00 vs. 0.20 mL/min, p = 0.005) and Qss (median: 0.20 vs. 0.50 mL/min, p = 0.025) were significantly lower in patients with pSD. Four of the five patients with pSD were anti-SSA negative, and routine blood parameters showed no significant differences. Borderline or positive antinuclear antibodies (ANA) were detected in 17.5% (n = 14) of patients with BMS and 40.0% (n = 2) of those with pSD (p = 0.025). Conclusions: Previously unrecognized pSD was identified in approximately 6% of patients with BMS. Sialometry was a more informative screening tool than burning intensity or routine laboratory tests. Assessment of whole salivary flow may help identify patients with oral burning who warrant rheumatologic evaluation before a diagnosis of BMS is confirmed.