What are the potential causes of burning mouth syndrome?

Potential Causes of Burning Mouth Syndrome

Burning mouth syndrome (BMS) can be classified as primary (idiopathic) when no underlying cause can be identified, or secondary when specific local, systemic, or psychological factors contribute to the condition. 1, 2

Primary (Idiopathic) BMS

Primary BMS is believed to have a neuropathic basis with no identifiable cause:

• Neurophysiological testing, biopsies, and functional MRI suggest it is a disorder of peripheral nerve fibers with central brain changes 3
• Possible dysfunction in the dopaminergic system 4
• Peripheral nerve damage may play a role in the pathogenesis 4

Secondary BMS

Secondary BMS can be attributed to various factors:

Local Factors

• Oral candidiasis (fungal infections) 3
• Mucosal lesions 3, 1
• Mechanical irritation from dental appliances 2
• Local oral infections 5
• Denture-related lesions 5

Systemic Factors

• Hematological disorders (anemia, vitamin B12, folate, or iron deficiency) 3
• Autoimmune disorders 3
• Hormonal changes associated with menopause (predominantly affects peri- and post-menopausal women) 1, 5
• Nutritional deficiencies (zinc, vitamins) 2, 5
• Diabetes mellitus 5

Pharmacological Factors

• Medication side effects (particularly those affecting salivary flow) 3
• ACE inhibitors 1
• Neuroleptics 1

Psychological Factors

• Anxiety 4
• Depression 3, 1
• Stress 4
• Psychological disorders 4

Associated Symptoms and Conditions

• Xerostomia (dry mouth) 3, 1
• Dysgeusia (taste disturbances) 3, 1
• Poor quality of life 3, 1

Diagnostic Considerations

• BMS is diagnosed primarily through exclusion of other potential causes 1, 4
• The condition typically affects the tongue tip, lateral borders, lips, palate, and buccal mucosa 1, 2
• The oral mucosa appears normal despite burning symptoms 1, 2
• Pain severity ranges from mild to severe 3, 1
• Sometimes eating can aggravate symptoms, while in other cases it may provide relief 3

Clinical Pearls and Pitfalls

• Multiple concurrent causes may be present in more than one-third of patients, making diagnosis challenging 5
• Professional delays in diagnosis and management are common 5
• The prognosis is generally poor with only a small number of cases resolving fully 3
• Patients can be reassured that the condition typically will not worsen, which is crucial for managing anxiety 3, 1
• A multidisciplinary approach involving dental specialists, neurologists, and mental health professionals is often necessary for effective management 1, 5