Unraveling Burning Mouth Syndrome

A 73-year-old patient presented with 4 months of intermittent burning oral pain.The pain was superficial involving the oral mucosa, tonsils and tongue and associated with dry mouth, without other alleviating or exacerbating factors.Prior medical history includes diabetes mellitus type 2, dyslipidemia, hypertension, coronary artery disease, pulmonary emphysema, obstructtive sleep apnea, insomnia, anxiety, orolabial herpes simplex virus infection, stimulant abuse disorder, opioid abuse disorder and current smoking.Examination of the oral cavity revealed normal, moist mucosa, without oral or orolabial lesions.Cranial nerve examination showed no focal deficits.Laboratory testing included Hgb A1c 7.1%, serum iron 43 mcg/dL, iron binding capacity (TIBC) 400 mcg/dL, iron saturation 11% and ferritin 12 ng/mL.Despite low iron, there was no anemia or microcytosis.Hemoglobin was 13.1 g/dL, hematocrit 41.0% with MCV of 92.8 fL.Comprehensive metabolic panel, TSH, folic acid, zinc, thiamine, pyridoxine and cobalamin were all within normal limits.Testing for anti-SSA/SSB Ab, anti-transglutaminase Ab and anti-gliadin Ab was negative.The patient was started on iron replacement and topical benzocaine lozenges as needed for pain.Dental evaluation was also advised to exclude dental causes.