Mucous membrane pemphigoid — ORE Part 1 MCQ

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HardOral Medicine and Oral PathologyMucous membrane pemphigoidORE Part 1

A 70-year-old woman presents with persistent desquamative gingivitis. She develops tense gingival blisters that rupture, leaving shallow erosions, and reports persistent grittiness of both eyes. Incisional biopsies are planned from lesional tissue for routine histology and from perilesional mucosa for direct immunofluorescence. What is the most likely diagnosis?

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Correct answer: B — Mucous membrane pemphigoid

The diagnosis is **mucous membrane pemphigoid (MMP)**. It typically affects older adults and may present orally as desquamative gingivitis with subepithelial, therefore relatively tense, blisters that leave erosions. Ocular irritation is particularly important because MMP can involve the conjunctiva and may scar; it requires prompt specialist assessment. Diagnosis is supported by routine histology plus direct immunofluorescence of perilesional mucosa, which identifies linear immune deposits at the basement membrane zone. Plaque-induced gingivitis does not cause blisters or ocular disease. Aphthae are discrete recurrent ulcers rather than a chronic blistering gingivitis. Erosive lichen planus can cause desquamative gingivitis but does not characteristically produce tense bullae or ocular MMP-type disease. Pemphigus vulgaris causes fragile, flaccid intraepithelial bullae and erosions rather than tense subepithelial blisters.

Reference: Schmidt E, et al. European Guidelines (S3) on diagnosis and management of mucous membrane pemphigoid, initiated by the European Academy of Dermatology and Venereology – Part II. 2021. https://pubmed.ncbi.nlm.nih.gov/34309078/