Burning Mouth Syndrome Diagnosis and Characteristics

Primary Burning Mouth Syndrome

The American College of Physicians recommends that primary burning mouth syndrome (BMS) be considered a disorder of peripheral nerve fibers with central nervous system changes, confirmed through neurophysiological testing, biopsies, and functional MRI, affecting predominantly peri- and post-menopausal women 1
Primary BMS manifests as a continuous burning, stinging, or itchy sensation most commonly affecting the tongue tip bilaterally, lips, palate, and buccal mucosa, with normal-appearing oral mucosa on examination 1
Associated symptoms of primary BMS include dry mouth, abnormal taste, depression, and poor quality of life, with a significantly lower density of epithelial nerve fibers in tongue biopsies compared to controls 1, 2

Oral candidiasis, a fungal infection, can cause burning mouth symptoms, diagnosed by scraping and KOH preparation, and must be excluded before diagnosing primary BMS 1, 3
Mucosal lesions, including traumatic ulceration from sharp edges of residual roots/crowns, thermal burns, or chemical injury, can cause burning mouth symptoms and must be excluded 1, 4
Autoimmune diseases, such as Sjögren's syndrome and sicca syndrome, can manifest with oral burning and must be excluded before diagnosing primary BMS 1, 2, 5
Thyroid disorders, particularly hyperthyroidism, can cause tongue erythema and burning, and must be excluded before diagnosing primary BMS 3
Pharmacological side effects from various medications can cause oral burning and must be excluded before diagnosing primary BMS 1
Post-traumatic trigeminal neuropathic pain and post-herpetic neuralgia can cause burning mouth symptoms and must be excluded before diagnosing primary BMS 1
Scarlet fever and Kawasaki disease can present with oral burning symptoms and must be excluded before diagnosing primary BMS 3

A detailed clinical history focusing on onset timing, medication use, systemic diseases, and dental procedures is essential for diagnosing BMS 4, 2
A thorough oral examination to identify mucosal lesions, candidiasis, or traumatic factors is necessary for diagnosing BMS 1, 4
Qualitative sensory testing may be considered if a neuropathic etiology is suspected 1
A biopsy may be considered if mucosal abnormalities are present or the diagnosis is uncertain 1, 4

The British Journal of Anaesthesia recommends ordering a complete blood count with differential to identify anemia, which commonly causes oral burning symptoms 6
Vitamin B12 levels should be checked as deficiency is a well-established cause of secondary burning mouth syndrome, according to the British Journal of Anaesthesia 6
Iron studies (ferritin, serum iron, TIBC) are necessary as iron deficiency anemia frequently presents with burning tongue, as stated by the British Journal of Anaesthesia 6

Elevated IgE levels may be present but are nonspecific findings in many conditions related to secondary eosinophilia and should not be routinely ordered unless specific allergic or parasitic conditions are suspected, as noted by the Journal of the National Comprehensive Cancer Network 7

Deficiency of riboflavin (vitamin B2) can manifest with glossitis, cheilosis, and angular stomatitis, particularly in patients with poor dietary habits 8
Deficiency of pyridoxine (vitamin B6) can cause glossitis, seborrheic dermatitis with cheilosis, and angular stomatitis, often seen in individuals with inadequate nutrition 9
Deficiency of zinc can lead to glossitis, alterations in taste, and hair loss, highlighting the importance of zinc supplementation in patients with suspected deficiency 10

Exposure of the oral mucosa to acidic or alkaline substances can cause erythema, edema, and pain on the tongue through the release of inflammatory mediators, as reported by the American Academy of Otolaryngology‑Head and Neck Surgery. 11

Herpes zoster oticus (Ramsay Hunt syndrome) may present with severe ear pain, vesicular lesions in the external auditory canal, facial nerve paralysis, and loss of taste on the anterior two‑thirds of the tongue, according to the American Academy of Otolaryngology‑Head and Neck Surgery. 11

Allergic contact dermatitis triggered by metals (e.g., nickel, silver), cosmetic or soap chemicals, plastics, or certain drugs can produce maculopapular and eczematous skin eruptions on the oral mucosa, as described by the American Academy of Otolaryngology‑Head and Neck Surgery. 11