Geographic Tongue

Geographic tongue (benign migratory glossitis, erythema migrans) is a common, benign inflammatory condition of the dorsal and lateral tongue characterised by irregular, well demarcated red patches of filiform papillary atrophy surrounded by white to yellow raised borders, which change shape and position over days to weeks.

Prevalence is 1 to 3 percent of adults, with a female predominance and higher rates in non-smokers, children, and people with atopy.

The cause is unknown. Associations include psoriasis (the histology is identical to psoriasiform mucositis), fissured tongue, atopy, allergic rhinitis, asthma, diabetes mellitus, hormonal factors (oral contraceptives, pregnancy), stress, vitamin B12, folate, iron and zinc deficiency, and a family history. It is a chronic relapsing condition without malignant potential.

Lesions tend to persist for months to years and resolve spontaneously, although they commonly recur.

• Multiple smooth, red, depapillated patches with white serpiginous borders on the dorsum and lateral margins of the tongue; migratory pattern over hours to days.

• Asymptomatic in about half; others have burning or stinging with hot, spicy, acidic or salty foods, or toothpaste.

• Occasionally other mucosal sites (ectopic geographic stomatitis on buccal mucosa, palate, floor of mouth).

• Fissured tongue is frequent; no lymphadenopathy, systemic features or fever.

• Clinical diagnosis in most cases from the characteristic pattern and the observation of change over time (photographs).
• Examination of the full oral cavity and skin for psoriasis.
• Biopsy only if atypical: histology shows epithelial hyperplasia with neutrophil containing microabscesses (Munro like) in the spinous layer, parakeratosis and a lymphocytic infiltrate in the lamina propria.
• Swab or smear for Candida species (KOH) if erythema persists and is painful.
• Blood tests if symptomatic: full blood count, ferritin, vitamin B12, folate, zinc, glucose or HbA1c.
• Patch testing for contact allergy to dental materials, flavourings (cinnamon) or toothpaste ingredients, if suspected.
• Exclude oral candidiasis, atrophic glossitis (nutritional), lichen planus, leukoplakia, erythroplakia, lupus, scarlet fever, and carcinoma in situ.

• Reassurance that the condition is benign, non-infectious and not cancerous is the principal treatment for asymptomatic patients; no drug treatment is needed.
• Avoid triggers: spicy, acidic and hot foods, alcohol, strongly flavoured toothpaste (switch to sodium lauryl sulfate free, mild flavoured paste), and tobacco.
• Symptomatic relief: benzydamine hydrochloride 0.15 percent oral rinse 15 mL swished for 1 to 2 minutes every 3 hours as needed (up to 7 days); topical lidocaine 2 percent viscous 5 mL swish and spit before meals when needed (avoid swallowing).
• Topical corticosteroid for persistent burning: triamcinolone acetonide 0.1 percent in adhesive paste applied thinly to the lesions 3 to 4 times daily after meals for 2 weeks, or betamethasone sodium phosphate 0.5 mg soluble tablet dissolved in 10 mL water as a rinse twice daily for 2 weeks; dexamethasone 0.5 mg in 5 mL rinse is an alternative.
• Candida co-infection: nystatin oral suspension 100 000 units/mL, 1 mL (adults 5 mL) four times daily for 7 to 14 days, or miconazole oral gel 20 mg/g, 2.5 mL four times daily for 14 days.
• Nutritional deficiency: replace iron (ferrous sulfate 200 mg three times daily), vitamin B12 (hydroxocobalamin 1 mg intramuscularly alternate days for 2 weeks, then every 3 months, or oral 1 mg daily), folate (5 mg daily for 4 months), zinc sulfate 220 mg daily for 8 weeks.
• Refractory painful cases: topical tacrolimus 0.1 percent ointment twice daily for 4 to 8 weeks, or systemic therapy under specialist advice (for example, in association with psoriasis).
• Follow up: review at 4 to 6 weeks if treated; annual oral examination.
• Counselling: lesions will move and recur and the condition does not become cancer; return if persistent painful lesion over 3 weeks.