Angular cheilitis — Viva

Q1: Definition, classification, and pathophysiology (3 min)

• Define angular cheilitis (perleche, angular stomatitis, cheilosis) and name the structures involved. (Inflammatory disorder of the labial commissures — the angles of the mouth, straddling vermilion and perioral skin; presents as erythematous, fissured, crusted, painful lesions.)
• How do you classify angular cheilitis by aetiology? (Infectious — Candida albicans, Staphylococcus aureus, streptococci; non-infectious/nutritional — iron, B12, folate, riboflavin deficiency; mechanical/anatomical — overclosure, ill-fitting dentures; systemic/immunological — diabetes, HIV, xerostomia, IBD.)
• Describe the pathogenic cascade. (Three steps: (1) anatomical predisposition to saliva pooling — decreased vertical dimension from overclosure or ill-fitting dentures creates commissural folds; (2) maceration — chronic saliva exposure breaks down the stratum corneum; (3) microbial colonisation — typically Candida albicans, sometimes with S. aureus seeded from anterior nares. Mixed infection is common.)
• Why is the commissure specifically predisposed? (It is a dependent recess where saliva pools by gravity; the macerated, warm, moist environment favours microbial growth; skin here is thinner and more fragile than elsewhere on the face.)
• How does iron deficiency contribute at the cellular level? (Impairs epithelial cell turnover and reduces cell-mediated immunity, allowing the colonisation cascade to proceed unchecked. In Plummer-Vinson syndrome, angular cheilitis accompanies dysphagia and oesophageal webs.)

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Q2: Clinical presentation and differential diagnosis (3 min)

• Describe the classical morphology. (Erythematous, macerated, fissured plaque with greyish-white surface (macerated stratum corneum) and yellowish crusting; a linear fissure (rhagade) in the commissural crease causes pain on mouth opening.)
• Is it typically unilateral or bilateral? (Bilateral is the rule. Unilateral suggests local trauma, HSV (vesicular onset), or SCC (indurated, non-healing).)
• Differentiate angular cheilitis from contact/allergic cheilitis. (Contact cheilitis affects the entire vermilion border (not just commissures); eczematous morphology; history of allergen exposure — lip balm, toothpaste, nail varnish, foods like mango; patch test positive.)
• Differentiate from actinic cheilitis. (Actinic cheilitis is a premalignant keratinocyte dysplasia of the lower lip vermilion from chronic UV exposure; elderly fair-skinned outdoor workers; blurring of vermilion border, scaling, atrophy, white plaques; confined to lower lip (sun-exposed); biopsy mandatory to exclude SCC.)
• When must you suspect squamous cell carcinoma? (Unilateral, indurated, non-healing ulcer or nodule with rolled everted edge and friable base; in elderly patients with sun damage, tobacco, or betel quid use; biopsy if not healed within two to four weeks.)
• What is orofacial granulomatosis / Melkersson-Rosenthal syndrome? (Non-caseating granulomatous inflammation causing persistent lip/facial swelling, fissured tongue (scrotal tongue), and recurrent facial nerve palsy; associated with Crohn disease; biopsy shows granulomas.)

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Q3: Investigations (2 min)

• Is angular cheilitis a clinical diagnosis? When are investigations warranted? (Yes, primarily clinical. Investigate if persistent (over two weeks despite therapy), recurrent, or with systemic clues.)
• State the first-line investigation panel. (FBC, serum ferritin, vitamin B12, folate, and HbA1c — interpreted against local laboratory cut-offs — plus oral/commissural swab for bacterial and fungal culture.)
• When do you take a swab and what do you look for? (If resistant to first-line therapy — identify Candida species (including non-albicans, azole-resistant) and S. aureus (including MRSA). Swab anterior nares if recurrent staphylococcal disease (nasal carriage).)
• When do you test for HIV? (If risk factors, recurrent candidiasis, or concurrent oral thrush and oral hairy leukoplakia. Fourth-generation antigen/antibody combination test.)

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Q4: Management — definitive and stepwise (3 min)

• What is the first-line topical antifungal and why? (Miconazole gel — preferred because it has BOTH antifungal and weak antibacterial activity, covering Candida and Staphylococcus; use per the local formulary regimen. Clotrimazole is purely antifungal.)
• Name the critical drug interaction with miconazole. (Miconazole inhibits CYP2C9 — it potentiates warfarin (INR elevation, bleeding risk) and interacts with sulfonylureas and statins. Check the drug chart; prefer nystatin or clotrimazole in anticoagulated patients.)
• When do you add a topical antibacterial and which? (If swab confirms S. aureus or empirically for yellow crusting: topical fusidic acid or mupirocin per local formulary. For nasal carriage, mupirocin nasal ointment for decolonisation.)
• When is oral fluconazole indicated? (Refractory disease despite topical therapy, or immunocompromised patients — oral fluconazole per local guidance. Check LFTs and drug interactions.)
• Describe the denture hygiene regimen. (Remove at night; brush daily with non-abrasive denture cleaner; soak overnight in chlorhexidine or dilute hypochlorite. The denture is a Candida reservoir — treating the mouth without treating the denture invites recurrence.)
• What are the nutritional replacement principles? (Replace iron, B12 (intramuscular hydroxocobalamin), and folate per local guidance. Always correct B12 before folate — folate alone can precipitate subacute combined degeneration of the cord.)

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Q5: Special populations, complications, and pitfalls (2 min)

• How does angular cheilitis present in HIV/AIDS? (May be severe, bilateral, and rapidly progressive, with concurrent oral candidiasis; topical therapy alone is often insufficient — use oral antifungals alongside antiretroviral therapy.)
• Why is diabetes a risk factor and how does it change management? (Hyperglycaemia impairs neutrophil function and promotes Candida adherence. Optimise glycaemic control — candidiasis is unlikely to resolve with persistent hyperglycaemia. Screen for genital candidiasis.)
• Name three pitfalls in management. ((1) Treating infection without correcting the cause. (2) Missing the miconazole-warfarin interaction. (3) Using topical corticosteroids (worsen Candida, mask SCC, cause skin atrophy). (4) Failing to biopsy a non-healing unilateral lesion (missing SCC).)
• What is the prognosis with appropriate treatment? (Excellent when the underlying cause is addressed; lesions recur if the cause is left uncorrected.)

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References2ShowHide

1. [1]Cabras M, Gambino A, Broccoletti R, et al. Treatment of angular cheilitis: A narrative review and authors' clinical experience Oral Dis, 2020.PMID 31464357
2. [2]Riad A, Kassem I, Issa J, et al. Angular cheilitis of COVID-19 patients: A case-series and literature review Oral Dis, 2022.PMID 33043573