Usefulness of pepsin saliva measurement for the detection of primary burning mouth syndrome related to reflux

Objectives: To study the diagnostic value of salivary pepsin tests for detecting laryngopharyngeal reflux (LPR) in patients with primary burning mouth syndrome (BMS). Methods: Patients with BMS and asymptomatic individuals were consecutively recruited from September 2018 to June 2023. Patients underwent hypopharyngeal-esophageal impedance pH-monitoring (HEMII-pH) and saliva collections to measure pepsin. Stomatology evaluation was carried out to exclude other causes of BMS. Oral, pharyngeal and laryngeal signs and symptoms were evaluated with Reflux Sign Assessment (RSA) and Reflux Symptom Score (RSS). Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of pepsin test were calculated considering the highest values of pepsin tests at ≥ 16, ≥ 36, and ≥ 100 ng/mL cutoffs. Receiver operating characteristic curve (ROC) was evaluated. Results: Forty-nine patients with both BMS and LPR at the HEMII-pH and 21 asymptomatic individuals were recruited. Pepsin test was 83.7%, 79.6%, and 71.4% sensitive at cutoffs ≥ 16, ≥ 36, and ≥ 100 ng/mL, respectively. The ROC analysis reported that a threshold of ≥ 21.5 ng/mL was associated with sensitivity, specificity, PPV and NPV of 81.6%, 81.0%, 90.1% and 65.4%, respectively. The severity score of burning mouth symptom was significantly associated with the saliva pepsin concentration (r s = 0.263; p = 0.029) and the oral RSA (r s = 0.474; p = 0.007). Conclusion: Pepsin test is a valuable diagnostic approach for detecting LPR in patients with BMS. Patients with high level of saliva pepsin reported more severe burning mouth symptoms. Future studies are needed to confirm the role of LPR in the primary BMS.