Median Rhomboid Glossitis

Median rhomboid glossitis (central papillary atrophy of the tongue) is a chronic erythematous, rhomboid or oval area of papillary atrophy in the midline of the dorsal tongue immediately anterior to the circumvallate papillae. It was once ascribed to a developmental failure of the tuberculum impar to be covered by lateral lingual swellings, but is now accepted as a form of chronic oral candidiasis (Candida albicans in over 85 percent of cases). Prevalence is about 1 percent in adults, mostly in men aged 30 to 60 years.

Predisposing factors: smoking (the commonest risk), inhaled corticosteroids (poor spacer and mouth rinse use), diabetes mellitus, HIV infection (especially at low CD4 counts), denture wearing, broad spectrum antibiotics, immunosuppression, xerostomia, and malnutrition. A nodular variant may mimic a tumour. The lesion is chronic, may persist for years and often recurs after treatment. It is benign, but biopsy is needed when nodular or atypical.

• Well demarcated, red, smooth, rhomboid or oval patch (1 to 3 cm) in the midline of the posterior dorsal tongue anterior to the circumvallate papillae, devoid of filiform papillae.
• May be flat, lobulated or nodular, with a hard feel.
• Asymptomatic in most patients; burning, soreness or altered taste may occur.
• Candidal involvement of the palate may coexist: a "kissing lesion" on the hard palate opposite the tongue lesion.
• Red flags: nodular or ulcerated lesion, induration, bleeding, rapid growth, lymphadenopathy, failure to respond to antifungal therapy.

• Clinical diagnosis by location and appearance.
• Swab, smear (KOH or Gram stain showing hyphae and pseudohyphae), or oral rinse culture for Candida species, with sensitivity testing in refractory cases.
• Test for predisposing disease: fasting glucose or HbA1c, HIV test with CD4 count, full blood count and iron studies, vitamin B12 and folate.
• Biopsy for nodular lesions, atypical features, or those that do not respond to antifungal therapy after 4 to 6 weeks: parakeratosis, pseudoepitheliomatous hyperplasia, candidal hyphae in the keratin layer (periodic acid-Schiff stain), and chronic inflammation; exclude squamous cell carcinoma, granular cell tumour, and lymphoma.
• Exclude geographic tongue, atrophic glossitis (nutritional), granular cell tumour, syphilitic glossitis, lingual thyroid (technetium scan), haemangioma, and carcinoma.

• Remove risk factors: stop smoking, improve oral hygiene, control diabetes, use spacer and rinse the mouth after inhaled steroids, treat HIV (antiretroviral therapy), and review drugs.
• First line topical antifungal: miconazole oral gel 20 mg/g, 2.5 mL (children 1.25 mL) held in the mouth near the lesion for 1 minute then swallowed, 4 times daily for 14 days (continue 7 days after resolution); or nystatin oral suspension 100 000 units/mL, 5 mL four times daily for 14 days (swish and swallow); or clotrimazole 10 mg troche dissolved slowly 5 times daily for 14 days.
• Persistent or extensive lesions: fluconazole 100 to 200 mg orally once daily for 7 to 14 days (children 3 to 6 mg/kg on day 1, then 3 mg/kg daily); check liver enzymes in prolonged courses and drug interactions (warfarin, statins, phenytoin).
• Refractory or fluconazole resistant: itraconazole oral solution 200 mg once daily for 14 days (take on an empty stomach), or posaconazole 400 mg twice daily for 3 days (loading) then 400 mg daily for 7 days.
• Antiseptic rinse: chlorhexidine 0.2 percent 10 mL twice daily for 14 days (do not use together with nystatin at the same time, since chlorhexidine reduces its activity; separate by 30 minutes).
• Dentures: remove at night, soak in sodium hypochlorite 0.1 percent for 15 minutes daily, and treat the denture surface.
• Nodular, indurated or non-responsive lesions: biopsy and surgical excision when required.
• Follow up: review at 2 and 6 weeks; the red patch may remain as a smooth atrophic area after the Candida is cleared; recurrences are frequent, and the long term patient must stay smoke free.
• Counselling: treatment of the yeast and removal of risk factors resolve most cases; the lesion is harmless, but any change needs prompt review.