What is the differential diagnosis (ddx) of angular cheilitis?

Differential Diagnosis of Angular Cheilitis

The differential diagnosis of angular cheilitis includes infectious causes (mixed Candida with Staphylococcus aureus or beta-hemolytic streptococci being most common), nutritional deficiencies (riboflavin, iron, B12), systemic diseases (diabetes, HIV, Crohn's disease, Kawasaki disease), mechanical factors (ill-fitting dentures, loss of vertical dimension), contact dermatitis, and in persistent cases, premalignant conditions like actinic cheilitis or dysplasia. 1, 2, 3

Primary Infectious Etiologies

Mixed infections dominate the infectious differential:

• Candida species combined with Staphylococcus aureus or beta-hemolytic streptococci represents the most common infectious cause, particularly in children 1
• Fungal infection alone (primarily Candida albicans) can present with erythema and white plaques extending beyond the commissures 1, 2
• Pure bacterial infection with Staphylococcus aureus or streptococci can occur without fungal co-infection 3

Nutritional and Metabolic Causes

Deficiency states must be considered:

• Riboflavin (vitamin B2) deficiency is a classic association with angular cheilitis 2
• Iron deficiency anemia commonly presents with angular cheilitis 2, 4
• Vitamin B12 deficiency can manifest as cheilitis as part of systemic anemia 4

Systemic Disease Associations

Multiple systemic conditions predispose to angular cheilitis:

• Diabetes mellitus increases risk through immunosuppression and altered oral flora 1
• HIV infection or immunosuppressive therapy creates vulnerability to opportunistic infections 1
• Crohn's disease can present with angular cheilitis as an extraintestinal manifestation 1
• Kawasaki disease should be considered in febrile children when angular cheilitis accompanies strawberry tongue, conjunctivitis, rash, and lymphadenopathy 1
• Sjögren's syndrome causes xerostomia that predisposes to angular cheilitis 5, 4

Mechanical and Local Factors

Physical factors contribute significantly:

• Ill-fitting dentures or loss of vertical dimension creates chronic moisture and maceration at commissures 3
• Lip licking or mouth breathing habits maintain chronic moisture 3
• Drooling (particularly in elderly or neurologically impaired patients) creates persistent irritation 6

Contact and Irritant Causes

Allergic and irritant reactions must be excluded:

• Contact dermatitis from dental materials, cosmetics, or topical medications 7, 4
• Irritant cheilitis from chronic exposure to saliva or environmental factors 7, 4

Critical Premalignant Considerations

Persistent lesions warrant biopsy:

• Actinic cheilitis is a premalignant condition requiring different treatment approaches and must be distinguished from angular cheilitis 3
• Dysplasia or malignancy should be excluded when lesions persist beyond 2 weeks despite appropriate treatment 1

Key Diagnostic Features to Assess

Examination should systematically evaluate:

• Bilateral versus unilateral involvement (bilateral suggests systemic or mechanical cause; unilateral raises concern for malignancy) 1
• Presence of fissures, crusting, or white plaques helps distinguish fungal from bacterial predominance 1
• Extension beyond commissures suggests more extensive fungal infection 1
• Associated oral findings such as denture stomatitis, glossitis, or other mucosal lesions 5, 4

Common Diagnostic Pitfalls

Avoid these errors:

• Assuming all cases are purely infectious without investigating underlying systemic causes or nutritional deficiencies 2, 3
• Failing to biopsy persistent lesions beyond 2 weeks of appropriate treatment, missing premalignant or malignant conditions 1
• Overlooking mechanical factors like denture fit or occlusal vertical dimension that perpetuate the condition 3
• Missing immunocompromised states that require more aggressive evaluation and treatment 1, 3