Angular cheilitis — SAQ

Stem

A 78-year-old edentulous woman presents with a four-week history of painful, cracked lesions at both corners of her mouth. She wears a full set of dentures that she has not had adjusted in over fifteen years, and she sleeps in them overnight. She has noticed progressive fatigue, breathlessness on exertion, and a sore tongue over the past three months. Her diet is poor — she lives alone and eats mainly tea and toast. On examination, there are bilateral erythematous, macerated, fissured lesions at both oral commissures with greyish-white borders and yellow crusting. Her tongue is smooth, pale, and beefy-red (atrophic glossitis). The palatal mucosa under her denture is diffusely erythematous. There are no vesicles, no induration, and no cervical lymphadenopathy. Investigations: haemoglobin 92 g/L (115 to 150), MCV 72 fL (80 to 100), ferritin 8 micrograms per litre (15 to 200), vitamin B12 340 ng per litre (200 to 900), folate 12 micrograms per litre (over 4), HbA1c 38 mmol per mol (under 48). A commissural swab grows Candida albicans and Staphylococcus aureus.

Questions

a) What is the diagnosis, and what three factors are contributing to it? Justify each from the stem. (3 marks) The diagnosis is angular cheilitis (perleche, angular stomatitis). Three contributing factors, each supported by the stem:

1. Mechanical/anatomical (overclosure from ill-fitting dentures): She has been edentulous with the same unadjusted dentures for over fifteen years — the dentures have lost vertical dimension, causing mandibular overclosure and deep commissural folds that trap saliva. The diffusely erythematous palatal mucosa (denture stomatitis) confirms chronic Candida colonisation of the denture.
2. Nutritional deficiency (iron deficiency): She has iron deficiency anaemia — microcytic (MCV 72), low haemoglobin (92), and severely low ferritin (8 micrograms per litre). The atrophic glossitis (smooth, beefy-red tongue) is a direct mucosal manifestation. Her poor diet (tea and toast, lives alone) is the likely cause. Iron deficiency impairs epithelial integrity and cell-mediated immunity.
3. Infectious (Candida plus Staphylococcus): The commissural swab confirms mixed infection with Candida albicans and Staphylococcus aureus. The greyish-white borders suggest Candida maceration; the yellow crusting suggests staphylococcal superinfection.

^{[1] [2]}

^[1][2]b) Outline the definitive management. Give the specific drugs, doses, routes, durations, and non-pharmacological measures. (4 marks) Management must treat the infection AND correct the cause simultaneously:

Treat the infection:

1. Topical miconazole gel applied to both commissures per the local formulary regimen — this is first-line and has both antifungal and antibacterial activity, covering both Candida and Staphylococcus. Also apply miconazole gel to the denture fitting surface and palatal mucosa (for denture stomatitis).
2. If the yellow crusting persists, add topical fusidic acid for the staphylococcal component.

^[1]Correct the cause: 3. Iron replacement: oral iron (e.g. ferrous sulfate) per local guidance — recheck Hb and ferritin after starting treatment. 4. Denture management: refer to a prosthodontist for relining, rebasing, or remaking to restore the correct vertical dimension and eliminate commissural folds. Denture hygiene: remove at night, brush daily with non-abrasive cleaner, and soak overnight in chlorhexidine or dilute hypochlorite to reduce the Candida reservoir on the acrylic. 5. Barrier protection: petrolatum-based lip balm applied frequently to reduce pain and promote fissure healing.

c) What is the significance of the MCV and ferritin results, and what further haematological or systemic condition should be excluded? (2 marks) The MCV of 72 fL (microcytic, below the reference range of 80 to 100) and ferritin of 8 micrograms per litre (severely depleted, well below the threshold of 15) confirm iron deficiency anaemia. The low MCV distinguishes iron deficiency from B12 or folate deficiency (which would be macrocytic — and indeed her B12 and folate are within normal limits). Further conditions to exclude: coeliac disease (tissue transglutaminase IgA — especially given her poor nutritional state and possible malabsorption), and Plummer-Vinson syndrome (sideropenic dysphagia with oesophageal webs and an increased risk of post-cricoid squamous cell carcinoma — ask about dysphagia and consider upper GI endoscopy). In an elderly woman with iron deficiency, colorectal cancer and upper GI malignancy must also be excluded with endoscopy and colonoscopy.^[2]

d) Name two pitfalls in managing this patient and explain why each matters. (1 mark)

1. Drug interaction pitfall — miconazole and warfarin: If this patient were on warfarin, miconazole (which inhibits CYP2C9) would dangerously elevate the INR and cause bleeding. Always check the medication list before prescribing miconazole; use nystatin or clotrimazole if the patient is anticoagulated.
2. Recurrence pitfall — treating the infection without correcting the cause: If only topical miconazole is given without denture correction and iron replacement, the angular cheilitis will recur within weeks because the saliva-pooling fold and the immune-impairing iron deficiency persist. Both pillars of treatment must be applied simultaneously.

References2ShowHide

1. [1]McReynolds DE, Moorthy A, Moneley JO, et al. Denture stomatitis-An interdisciplinary clinical review J Prosthodont, 2023.PMID 36988151
2. [2]Cabras M, Gambino A, Broccoletti R, et al. Treatment of angular cheilitis: A narrative review and authors' clinical experience Oral Dis, 2020.PMID 31464357