Cover image: Bilateral angular cheilitis in an elderly individual with false teeth, iron deficiency anemia and dry mouth | Matthew Ferguson - CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=45719116

Inflammation of one or both corners of the mouth.

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Aetiology

Infections

• Fungi:
  • Candida species (M/C cause, 93% cases)
    • M/C Candida albicans (20% cases)
• Bacteria:
  • Staphylococcus aureus (20% cases)
  • β-hemolytic streptococci (8–15% cases)
• Combination of the above (polymicrobial infection)
  • 60% of cases involving both C. albicans and S. aureus

Irritants

• Poorly fitting dentures
• Licking the lips or drooling
• Mouth breathing resulting in a dry mouth
• Sun exposure
• Overclosure of the mouth
• Smoking
• Minor trauma

Allergies

• Substances like toothpaste, makeup, and food

Other causes:

• Contact dermatitis
• Nutritional deficiencies
• Systemic disorders
• Drugs
• Allergic contact dermatitis
• Loss of lower facial height

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Clinical features

Variable appearance of lesions (commonly symmetrical on both sides)

Initial signs:

• Corners of the mouth develop a gray-white thickening and adjacent erythema

Later signs:

• Roughly triangular area of erythema
• Oedema and breakdown of skin at either corner of the mouth
• Fissured, crusted, ulcerated or atrophied mucosa of lip
• Bleeding usually absent
• Skin involvement:
  • Radiating rhagades (linear fissures) from the corner of the mouth
• Staphylococcus aureus involvement:
  • Golden yellow crusts
• Chronic angular cheilitis:
  • Suppuration (pus formation), exfoliation (scaling) and formation of granulation tissue

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Diagnosis

Investigations

Patch testing

Method used to determine whether a specific substance causes allergic inflammation of a patient’s skin. Any individual suspected of having allergic contact dermatitis or atopic dermatitis needs patch testing,

Blood tests

• Complete blood count (CBC)
• Levels of iron, ferritin, vitamin B12 (and possibly other B vitamins), and folate

Differential diagnosis

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Management

Potential reservoirs of infection inside the mouth are identified and treated

• Dentures properly fitted and disinfected

Increase the vertical dimension of the lower face to prevent overclosure of the mouth and formation of deep skin folds

• Construction of new dentures with an adjusted bite
• Resistant cases:
  • Surgical procedures (restore the normal facial contour):
    • Collagen injections
    • Facial fillers:
      • Autologous fat or crosslinked hyaluronic acid
  • Other measures:
    • Improving oral hygiene
    • Stopping smoking or other tobacco habits
    • Barrier cream (e.g. zinc oxide paste) at night

Treatment of the infection and inflammation of the lesions

• Topical antifungals:
  • Clotrimazole, amphotericin B, ketoconazole, or nystatin cream
  • Miconazole (has antibacterial action as well)
• Some antifungal creams are combined with corticosteroids:
  • Hydrocortisone or triamcinolone
• Diiodohydroxyquinoline
• Staphylococcus aureus infection:
  • Antibiotic cream:
    • Fusidic acid cream
  • Alternative antibiotics:
    • Neomycin, mupirocin, metronidazole, and chlorhexidine

If the condition appears resistant to treatment, investigations for underlying causes