What causes a tingling sensation in the mouth?

Oral Tingling: Differential Diagnosis and Management

You need to systematically exclude secondary causes before considering primary burning mouth syndrome (BMS), starting with a focused examination for oral candidiasis, mucosal lesions, and recent dental trauma, followed by laboratory testing for nutritional deficiencies (B12, iron, complete blood count). 1, 2

Immediate Clinical Assessment

Key History Elements to Obtain

• Timing and pattern: Continuous symptoms suggest neuropathic causes (post-traumatic trigeminal pain, BMS), while paroxysmal attacks indicate neuralgias 1
• Recent dental procedures: Root canals, extractions, or implants within 3-6 months suggest post-traumatic trigeminal neuropathic pain 1
• Medication review: Many drugs cause oral burning as a side effect 1, 2
• Menopausal status: Primary BMS predominantly affects peri- and post-menopausal women 1, 2

Physical Examination Priorities

• Inspect oral mucosa with good lighting: Normal-appearing mucosa suggests primary BMS or neuropathic pain; visible lesions indicate secondary causes 1
• Check for oral candidiasis: Perform scraping and KOH preparation if white patches or erythema present 2
• Palpate for traumatic sources: Sharp edges of teeth, ill-fitting dentures, or residual root fragments 2
• Test for light touch-evoked pain: Allodynia suggests post-herpetic neuralgia or post-traumatic trigeminal pain 1

Mandatory Laboratory Workup

Order these tests before diagnosing primary BMS: 2

• Complete blood count with differential (to identify anemia) 2
• Vitamin B12 level (deficiency is a well-established cause) 2
• Iron studies including ferritin, serum iron, and TIBC (iron deficiency frequently causes burning tongue) 2
• Thyroid function tests (hyperthyroidism can cause tongue erythema and burning) 2

Differential Diagnosis Algorithm

If Continuous Burning/Tingling Present:

Post-Traumatic Trigeminal Neuropathic Pain 1

• Develops within 3-6 months of dental procedure or facial trauma 1
• Burning, tingling quality, sometimes sharp 1
• May have allodynia or other sensory changes 1
• Management: Neuropathic pain medications (gabapentin, pregabalin, tricyclic antidepressants) 1

Post-Herpetic Neuralgia 1

• History of herpes zoster at the site 1
• Burning, tingling, itchy, tender, can be sharp 1
• Moderate to severe intensity 1
• Aggravated by light touch and eating 1
• Management: Neuropathic pain medications 1

Primary Burning Mouth Syndrome 1, 2

• Only diagnosed after excluding all secondary causes 2
• Bilateral tongue tip most common, also lips, palate, buccal mucosa 1, 2
• Normal-appearing oral mucosa on examination 1, 2
• Associated with dry mouth, abnormal taste, depression 1, 2
• Represents peripheral nerve fiber disorder with central nervous system changes 2
• Management: Reassurance that it will not worsen (crucial for patients), cognitive behavioral therapy, possibly neuropathic pain medications 1
• Prognosis: Poor, with only small number resolving fully 1

If Paroxysmal Sharp Attacks Present:

Trigeminal Neuralgia 1

• Sharp, shooting, electric shock-like pain lasting seconds to minutes 1
• Triggered by light touch, washing, cold wind, eating, brushing teeth 1
• Moderate to very severe intensity 1
• Management: Anticonvulsants (carbamazepine, oxcarbazepine), surgical options 1
• Imaging: MRI indicated to exclude vascular compression or mass 1

Critical Pitfalls to Avoid

• Do not diagnose primary BMS without excluding secondary causes: Oral candidiasis, nutritional deficiencies, autoimmune diseases, medication side effects, and thyroid disorders must be ruled out first 2
• Do not miss recent dental trauma history: Even minor procedures can cause persistent neuropathic pain that develops weeks to months later 1
• Do not overlook psychiatric comorbidity: Depression and anxiety are common with chronic oral pain and require prompt identification, as suicide is reported in patients with co-existing psychiatric illness 1, 3, 4
• Do not order imaging for non-localized, non-pulsatile symptoms without neurologic deficits: Imaging is not indicated for bilateral, symmetric oral tingling without focal neurological abnormalities 1

Treatment Failure Considerations

• Post-traumatic trigeminal pain has a high percentage of treatment failures even with standard neuropathic pain management 1
• Primary BMS has poor long-term prognosis, but reassuring patients that symptoms will not worsen is often crucial for quality of life 1
• Consider referral to specialized pain clinic if first-line neuropathic pain medications fail 1