Which deficiency can cause angular cheilitis (sores in the corners of the mouth)?

Angular Cheilitis: Nutritional Deficiencies

Riboflavin (vitamin B2) deficiency is the primary nutritional cause of angular cheilitis (sores in the corners of the mouth), though pyridoxine (vitamin B6), folate, and iron deficiencies can also produce this clinical finding. 1, 2

Primary Nutritional Deficiencies

Riboflavin (Vitamin B2)

• Riboflavin deficiency classically presents with angular cheilitis (angular stomatitis), along with glossitis, photophobia, and corneal vascularization. 1, 2
• Severe riboflavin deficiency clinically manifests as cheilosis, angular stomatitis, glossitis, seborrheic dermatitis, and severe anemia with erythroid hypoplasia. 2
• This deficiency is more common in low-income countries but subclinical deficiency may be widespread even in high-income settings. 2

Pyridoxine (Vitamin B6)

• Pyridoxine deficiency causes angular stomatitis, seborrheic dermatitis with cheilosis and glossitis, along with microcytic anemia and neurological symptoms. 1
• Populations at greatest risk include alcoholics, renal dialysis patients, the elderly, post-operative patients, and those on medications like isoniazid or corticosteroids. 1

Folate (Vitamin B9)

• Folate deficiency produces angular stomatitis, oral ulcers, glossitis, along with megaloblastic anemia and neuropsychiatric manifestations. 1
• When evaluating folate deficiency, always simultaneously assess for cobalamin (B12) deficiency, as treating folate alone can mask B12 deficiency and worsen neurological complications. 1

Iron Deficiency

• Iron deficiency is associated with angular cheilitis and should be considered in the differential diagnosis. 3

Clinical Approach

When to Suspect Nutritional Deficiency

• Consider nutritional deficiency when angular cheilitis occurs bilaterally with associated findings like glossitis, other oral mucosal changes, or anemia. 1
• Evaluate for risk factors: poor dietary intake, malabsorption, alcoholism, chronic kidney disease, medications that interfere with vitamin metabolism, or critical illness. 1

Diagnostic Workup

• Measure serum levels of riboflavin, pyridoxine (plasma pyridoxal 5-phosphate), folate (serum and RBC folate), vitamin B12, and iron studies in patients with angular cheilitis and suspected nutritional deficiency. 1
• Normal plasma pyridoxal 5-phosphate values are 20-200 nmol/L; serum folate should be ≥10 nmol/L and RBC folate ≥340 nmol/L. 1

Critical Pitfalls to Avoid

• Do not assume angular cheilitis is purely nutritional—it most commonly has a mixed infectious etiology with Candida species combined with Staphylococcus aureus or beta-hemolytic streptococci. 4, 3
• Lesions persisting beyond 2 weeks despite appropriate treatment warrant biopsy to exclude dysplasia or malignancy. 4
• In patients with macrocytic anemia, always measure both folate and B12 simultaneously to avoid masking B12 deficiency with folate supplementation alone. 1
• Consider systemic diseases: diabetes mellitus, HIV, immunosuppression, Crohn's disease, or Sjögren's syndrome can all predispose to angular cheilitis. 4, 3

Treatment Considerations

• For confirmed nutritional deficiency, oral supplementation with the deficient vitamin is appropriate: riboflavin, pyridoxine 50-100 mg daily for 1-2 weeks, or folate as indicated. 1
• First-line treatment for angular cheilitis typically requires combination antifungal and corticosteroid therapy to address the common infectious component, even when nutritional deficiency is present. 3
• Reassess after 2 weeks if no improvement occurs. 3