Causes of secondary burning mouth syndrome include Nutritional deficiency (vitamin B12, vitamin B9 [folate]) Anemia Diabetes mellitus Candida infection (candidiasis) Allergy (foods, dental products) Oral mucosal disorders (eg, stomatitis, lichen planus, pemphigoid, pemphigus vulgaris, neoplasia) Xerostomia Angiotensin-converting enzyme (ACE) inhibitors Oral parafunctional behavior (eg, tongue thrusting, clenching, bruxism) Burning mouth syndrome may cause burning, tingling, or numbness of the tongue, palate, lips, or other mucosal surfaces of the mouth, often bilaterally and sometimes in multiple foci.