Erosive Gingiva That Will Not Heal
Ms. R is a 56-year-old accountant who reports 8 months of sore, peeling gums. She avoids spicy foods and cannot tolerate her lower left partial denture. Examination shows diffuse erythema and desquamation of the attached gingiva on the buccal and lingual surfaces of both arches; the peripheral mucosa has faint white striae. There are no skin, ocular, genital, or nasal lesions. She takes lisinopril 20 mg daily, atorvastatin 40 mg nightly, and occasional ibuprofen 400 mg. She has no history of smoking, hepatitis, or recent dental work. Periodontal probing depths are 3 mm or less except 4 mm on tooth #19; radiographs show no periapical pathosis. A previous dentist prescribed amoxicillin and chlorhexidine without improvement. She asks whether she needs all her teeth removed. You suspect a mucocutaneous disease but need to confirm before committing to long-term topical steroids.
1. List your leading differential diagnoses and the specific clinical or historical features that would help separate them. What would you ask or examine next?
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Leading differential
- Oral lichen planus (OLP), erosive type.
- Mucous membrane pemphigoid (MMP).
- Pemphigus vulgaris (PV).
- Less likely: linear IgA disease, chronic ulcerative stomatitis, plasma cell gingivitis, drug-induced lichenoid reaction, lupus.
Discriminating features
- OLP: white striae at the periphery, symmetric, often buccal mucosa; skin lesions may be purple, pruritic, polygonal papules; nail pitting; no scarring.
- MMP: ocular involvement (dryness, redness, symblepharon), nasal or genital erosions, desquamative gingivitis that may scar; Nikolsky usually negative.
- PV: flaccid blisters, skin involvement, positive Nikolsky, severe pain; gingiva may be the first site.
- Drug-induced lichenoid: temporal relationship with lisinopril or NSAIDs; resolves after withdrawal.
Ask and examine Ask about eye symptoms, hoarseness, dysphagia, genital sores, skin blisters, new medications including checkpoint inhibitors, and response to previous steroids. Examine skin, scalp, nails, conjunctivae, nasal and genital mucosa; perform Nikolsky. Absence of extraoral disease does not exclude MMP or PV, so biopsy is required. The 4 mm probing depth at #19 is unlikely to explain diffuse desquamative gingivitis.
2. How would you perform the biopsy, and why is direct immunofluorescence essential? What pitfalls can produce a false-negative result?
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Perform two biopsies. For H&E, take an incisional specimen from the edge of an erosive area that includes white striae and adjacent normal mucosa; avoid the ulcer base, which shows only nonspecific inflammation. For direct immunofluorescence (DIF), take a separate specimen from clinically normal perilesional mucosa, place it in Michel's transport medium or Zeus solution, and do not put it in formalin. Do not use electrocautery or laser at the biopsy site.
DIF is essential because H&E alone cannot reliably separate OLP, MMP, and PV. Patterns: OLP shows a shaggy linear band of fibrinogen at the basement membrane; MMP shows linear IgG and C3 along the basement membrane; PV shows intercellular IgG in a chicken-wire pattern. False negatives occur if the specimen is taken from eroded mucosa, is too superficial, is placed in formalin, or is delayed. If DIF is negative but suspicion remains, repeat the biopsy or refer to oral pathology.
3. Assuming the diagnosis is oral lichen planus, outline your initial management and follow-up. What would make you escalate to systemic therapy or re-biopsy?
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Start topical clobetasol propionate 0.05% gel twice daily to affected gingiva for 2–4 weeks, or dexamethasone 0.5 mg/5 mL rinse 5 mL swish and spit twice daily. Add an antifungal such as nystatin or fluconazole if there is candidiasis, because steroids can precipitate it. Reinforce atraumatic hygiene, a soft brush, and avoidance of spicy or acidic foods. Reassess at 4–6 weeks.
Escalate if there is no improvement, if erosions persist, or if she cannot tolerate topical therapy: consider intralesional triamcinolone 10 mg/mL every 2–4 weeks or a short course of systemic prednisone 0.5–1 mg/kg with tapering. Do not use long-term systemic steroids without a confirmed diagnosis. Re-biopsy any persistent ulcer or indurated area to exclude dysplasia or malignancy. Long-term follow-up every 6–12 months is appropriate for OLP, with attention to smoking and alcohol. If DIF shows MMP or PV, refer for systemic immunosuppression and specialist care.