What are the causes and treatments of a sore tongue?

Causes and Treatment of Sore Tongue

A sore tongue is most commonly caused by nutritional deficiencies (iron, folate, vitamin B12, zinc), oral infections (candidiasis, viral), burning mouth syndrome, traumatic injury, or inflammatory conditions like oral lichen planus, and treatment should target the underlying cause after excluding secondary factors. 1, 2

Primary Causes to Evaluate

Nutritional Deficiencies (Most Common Treatable Cause)

• Iron, folate, vitamin B12, riboflavin, or niacin deficiency causes atrophic glossitis with tongue soreness, swelling, papillary atrophy, and surface changes 2, 3, 4
• Obtain complete blood count, serum iron, vitamin B12, and folate levels to identify deficiencies 5
• Zinc deficiency specifically affects salivary zinc levels and can cause geographic tongue with soreness 6
• Treatment with replacement therapy resolves symptoms and prevents irreversible systemic and neurologic damage 5, 3

Infectious Causes

• Oral candidiasis presents as white patches, erythema, or median rhomboid glossitis with soreness 2, 3
  • Treat with nystatin oral suspension 100,000 units four times daily for 1 week, or miconazole oral gel 5-10 mL held in mouth after food four times daily for 1 week 7
  • Fluconazole 100 mg/day for 7-14 days for resistant cases 8
• Oral hairy leukoplakia from Epstein-Barr virus in immunocompromised patients causes white corrugated lesions with discomfort 2, 3
  • Treat with oral antivirals 2, 3
• Herpes simplex or varicella-zoster virus causes painful ulcerations 4

Burning Mouth Syndrome

• Chronic burning sensation predominantly affecting the tongue tip bilaterally, lips, and palate in peri- and post-menopausal women 1
• Oral mucosa appears normal on examination 1
• Must exclude secondary causes first: oral candidiasis, mucosal lesions, haematological disorders, autoimmune disorders, and medication side-effects 1
• Associated with dry mouth, abnormal taste, depression, and poor quality of life 1
• Treatment options with evidence:
  • Gabapentin for neuropathic pain component 2
  • Topical clonazepam (held in mouth before swallowing) 2, 3
  • Capsaicin (though may cause gastric problems) 1, 2
  • Cognitive behavioral therapy 1, 2
  • Alpha-lipoic acid combined with gabapentin 300 mg showed best outcomes in one study 1
• Reassure patients it will not worsen—this reassurance alone is often crucial 1

Inflammatory and Reactive Conditions

• Oral lichen planus causes chronic inflammation with white reticular patterns or erosions, treated with topical or systemic corticosteroids and calcineurin inhibitors 2
• Geographic tongue (benign migratory glossitis) causes annular lesions with soreness, often associated with lower salivary zinc 2, 3, 6
  • Does not require treatment unless symptomatic 2, 3
• Traumatic injury from dental procedures, ill-fitting dentures, or chronic irritation 1

Post-Traumatic Neuropathic Pain

• Post-traumatic trigeminal neuropathic pain can occur after dental procedures (root canal, extractions, implants) with continuous burning or tingling 1
• Often history of poor analgesia during the procedure 1
• Treat with neuropathic pain medications, though high failure rate 1

Symptomatic Treatment for All Causes

Pain Relief

• Ibuprofen or paracetamol for acute symptom relief 1
• Viscous lidocaine 2%, 15 mL per application held in mouth for 1-2 minutes before spitting out 7
• Avoid eating or drinking for 30 minutes after topical anesthetic use 7

Oral Hygiene and Supportive Care

• Soft toothbrush or swab after meals and before sleep 1, 7
• Alcohol-free mouthwash (alcohol causes dehydration and irritation) 1, 7
• Chlorhexidine 0.2% mouthwash twice daily for inflammation 7
• Benzydamine hydrochloride rinse every 3 hours, particularly before eating, for anti-inflammatory effect 7, 8

Dietary Modifications

• Avoid irritants: smoking, alcohol, citrus fruits, tomatoes, hot drinks, spicy foods, raw or crusty foods 1, 7
• Drink ample fluids to keep mouth moist 1

Red Flags Requiring Biopsy or Referral

• Patients over 40 years with unilateral pain, induration, ulceration, or non-healing lesions, especially with tobacco/alcohol use 9
• Any suspicious lesion requires biopsy to exclude leukoplakia or squamous cell carcinoma 2, 3
• Persistent symptoms after 2 weeks of appropriate treatment warrant reevaluation 8
• Refer to oral and maxillofacial surgeon, otolaryngologist, or dentist experienced in oral pathology 2, 3

Common Pitfalls

• Do not diagnose specific nutritional deficiency on clinical impression alone—always obtain laboratory confirmation 5
• Do not use petroleum-based products chronically on oral mucosa as they promote dehydration and increase infection risk 8
• Do not assume all tongue soreness is benign—always evaluate for malignancy in appropriate risk groups 9, 2
• Multiple nutritional deficiencies often coexist, complicating the clinical picture 5