What is the best course of treatment for an older adult patient with a history of angle cheilitis presenting with a burning sensation on the tip of their tongue, potentially related to vitamin B12 deficiency or iron deficiency?

Burning Tip of Tongue with History of Angular Cheilitis

This presentation most likely represents burning mouth syndrome (BMS) secondary to nutritional deficiencies, particularly vitamin B12 or iron deficiency, which commonly coexist with angular cheilitis in older adults. 1, 2, 3

Immediate Diagnostic Approach

The combination of burning tongue tip and angular cheilitis strongly suggests underlying nutritional deficiency rather than primary BMS. 4, 5

Essential Laboratory Testing

Order the following tests immediately to identify treatable secondary causes:

• Complete blood count with differential to identify anemia 1, 3
• Vitamin B12 level - deficiency is a well-established cause of both burning tongue and angular cheilitis 1, 2, 3, 4
• Iron studies (ferritin, serum iron, TIBC) - iron deficiency frequently presents with burning tongue and angular cheilitis 1, 2, 3, 5
• Fasting glucose/HbA1c to exclude diabetic neuropathy 1, 2
• Thyroid function tests as hyperthyroidism can cause tongue burning 1, 2, 3

Clinical Examination Priorities

Perform a thorough oral examination focusing on:

• Assess for oral candidiasis - scraping and KOH preparation even without visible thrush, as candida can cause both conditions 2, 3
• Document tongue appearance - look for atrophic glossitis, erythema, or mucosal changes suggesting B12 deficiency 4, 6
• Evaluate angular cheilitis severity - note if bilateral, presence of fissuring, or secondary infection 7, 5
• Review all current medications for drugs causing oral burning as side effects 2, 3

Treatment Algorithm

If Vitamin B12 Deficiency Confirmed

Administer cyanocobalamin 100 mcg intramuscular or deep subcutaneous injection daily for 6-7 days, then alternate days for seven doses, then every 3-4 days for 2-3 weeks, followed by 100 mcg monthly for life. 8

• Avoid intravenous route as almost all vitamin will be lost in urine 8
• Oral B12 is not dependable in pernicious anemia or malabsorption 8
• Expect clinical improvement and reticulocyte response within the first week 8
• Oral manifestations including glossitis, glossodynia, burning sensations, and cheilitis typically improve with B12 replacement 4

If Iron Deficiency Confirmed

Treat with oral or intravenous iron replacement based on severity and inflammation status:

• In the absence of inflammation, ferritin <30 mcg/L or transferrin saturation <16% defines iron deficiency 9
• With inflammation present, ferritin <100 mcg/L with transferrin saturation <16% indicates iron deficiency 9
• Iron deficiency anemia commonly presents with burning tongue and angular cheilitis 1, 2, 5

If Candidiasis Identified

• Treat with topical or systemic antifungals as angular cheilitis and burning mouth can both result from candidal infection 3, 6
• Symptomatic median rhomboid glossitis usually improves with antifungals 6

If All Secondary Causes Excluded

Only after excluding nutritional deficiencies, candidiasis, medications, and systemic diseases should primary BMS be diagnosed:

• Gabapentin has shown improvement in burning mouth syndrome 6
• Topical clonazepam (not swallowed) has demonstrated efficacy 6, 10
• Capsaicin may provide relief 6, 10
• Alpha-lipoic acid has shown benefit in randomized controlled trials 10
• Cognitive behavioral therapy can help eliminate symptoms 6, 10

Critical Clinical Pearls

The presence of angular cheilitis makes nutritional deficiency highly likely and should never be dismissed as coincidental. 4, 5

• Angular cheilitis is associated with vitamin B12, iron, and other nutritional deficiencies that act in combination with local factors 5
• Oral manifestations of B12 deficiency including glossitis, glossodynia, burning sensations, and cheilitis can precede hematological symptoms 4
• Investigating vitamin B12 levels should be considered in patients presenting with oral burning sensations without apparent origin 4
• The tongue tip is the most common location for both primary BMS and B12 deficiency-related burning 1, 3

Common Pitfalls to Avoid

Do not diagnose primary BMS without first excluding all secondary causes through laboratory testing. 2, 3

• Failing to check B12 and iron levels in older adults with burning tongue and angular cheilitis is a critical error 1, 4
• Normal-appearing oral mucosa does not exclude nutritional deficiency as the cause 3, 4
• Treating empirically for primary BMS without workup will miss treatable deficiencies 2, 3
• Oral candidiasis can exist without visible thrush and requires scraping/culture for diagnosis 2, 3