Bilateral Erosive Gingivitis in a Woman Taking Lisinopril
A 63-year-old woman reports eight months of sore, 'peeling' gums that make eating spicy food painful. She has bilateral erythematous, erosive gingiva on the facial and lingual aspects of the premolar and molar regions, with white, lacy striae on both buccal mucosae. The palate, floor of the mouth, and skin are unaffected, and she has never noticed blisters. She takes lisinopril 20 mg daily for hypertension and has had a base-metal crown on tooth 46 for two years. She is a non-smoker, wears no dentures, and uses a herbal mouthwash. The gingiva bleeds easily, plaque scores are low, and probing shows no attachment loss. She asks whether she needs 'strong antibiotics' and whether the crown is the cause.
1. List your differential diagnosis and explain which features in the history and examination support or argue against each.
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1. Oral lichen planus (erosive/atrophic type). Strong support: bilateral symmetrical erosive gingiva with reticular white striae on the buccal mucosa - the striae are the diagnostic clue. Against: no skin lesions, though 15–25% of patients have none at presentation.
2. Lichenoid reaction - drug-induced. Lisinopril is a recognised but uncommon cause; a temporal relationship (eight months of symptoms vs long-standing medication) is weak but not excluded. The bilateral symmetry fits; unilateral or contact-limited disease would suggest a local cause.
3. Lichenoid contact reaction to the base-metal crown. Supported by the crown on 46 and possible metal allergy, but the lesions are bilateral and extend well beyond the crown's mucosa - this makes a pure contact reaction unlikely, though it can be a cofactor.
4. Mucous membrane pemphigoid. Desquamative gingivitis with intact or ruptured blisters is typical; the absence of ocular, nasal, or genital symptoms and of blistering argues against it, but it must still be excluded because untreated ocular involvement can scar.
5. Pemphigus vulgaris. Usually more widespread, with fragile blisters and skin involvement; less likely with strictly gingival, symmetrical erosions and no skin disease, but anti-desmoglein testing can exclude it.
6. Others: candidiasis (would usually be removable white plaque, often on the palate, and she is not obviously immunosuppressed), plasma cell gingivitis (a herbal mouthwash or cinnamon exposure could contribute), and, importantly, a drug-induced or autoimmune desquamative gingivitis masking a premalignant lesion - hence biopsy.
Antibiotics are not indicated: this is inflammatory/immune-mediated, not bacterial. Explain that clearly and address the herbal mouthwash as a possible irritant or allergen.
2. Describe the biopsy and laboratory work-up you would arrange, and what you would do while awaiting results.
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Biopsy. An incisional biopsy is appropriate - the disease is widespread and a single small sample is sufficient. Take two specimens if possible:
- One from lesional/perilesional mucosa in formalin for haematoxylin and eosin (to assess the epithelium, the band-like lymphocytic infiltrate, and any dysplasia).
- One from clinically normal perilesional mucosa in Michel's solution or Zeus fixative for direct immunofluorescence (DIF) - this is the decisive test for mucous membrane pemphigoid (linear IgG/C3 at the basement membrane) and pemphigus (intercellular IgG).
Serology. If pemphigus or pemphigoid is suspected, send blood for indirect immunofluorescence and desmoglein 1/3 ELISA; anti-BP180/BP230 ELISA may support pemphigoid. A full blood count, ferritin, B12/folate, and HbA1c are reasonable to exclude deficiency or diabetes contributing to mucosal fragility.
Referral. Urgent ophthalmology assessment if there is any eye discomfort, redness, or photophobia, and gynaecology referral if genital symptoms appear - scarring in either site is the reason MMP cannot be managed with watchful waiting.
While awaiting results. Stop the herbal mouthwash; consider, with her physician, substituting lisinopril if a drug reaction is plausible (do not stop antihypertensives unilaterally). Prescribe a topical corticosteroid (e.g., clobetasol 0.05% gel or triamcinolone in orabase) for symptomatic control, with an antifungal rinse to prevent candidiasis. Soft diet, sodium lauryl sulfate-free toothpaste, and analgesia as needed. Tell her the crown is under suspicion but not proven, and defer replacement until the biopsy is reported.
3. Assuming the biopsy confirms oral lichen planus, outline long-term management and the risk you must discuss with her.
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Control, not cure. Explain that oral lichen planus is chronic and immune-mediated, fluctuates, and is managed rather than eradicated.
Topical therapy. Use the lowest effective potency and frequency of topical corticosteroid, applied to dried mucosa, and taper when the disease settles. For persistent erosive disease, a short course of systemic corticosteroids or specialist agents (e.g., topical calcineurin inhibitors) may be used under oral medicine supervision. Treat or prevent secondary candidiasis, which is common with inhaled or topical steroids.
Trigger and irritant control. Meticulous but gentle hygiene, no harsh mouthwashes or alcohol-containing rinses, and repair of sharp cusps or ill-fitting restorations. Review medications for lichenoid potential at each visit. If the crown were shown to be the trigger, replacement would be justified - but only with evidence, not by assumption.
Monitoring and the risk to discuss. Oral lichen planus carries a small but real risk of malignant transformation - typically quoted around 1% (with wide variation in the literature and higher figures in erosive disease). This means:
- Review every 6–12 months, with photographic records and measurement of any change.
- Biopsy any persistent ulceration, induration, red or white change that does not respond to treatment, or any new focal lesion.
- Warn her explicitly: a non-healing sore, a lump, or bleeding in the same area warrants urgent review rather than another course of steroid.
Document the diagnosis, the advice given, the follow-up schedule, and her understanding. Coordinate with her physician regarding lisinopril if a drug-induced component remains possible.