Pathology · single question
A 27-year-old female with blisters throughout the oral cavity and a positive Nikolsky sign has a recent biopsy showing suprabasilar vesicles. All of the following are true regarding the lesions EXCEPT one. Which is the EXCEPTION?
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Correct answer: D. Definitive diagnosis should include mucous membrane pemphigoid
The clinical picture (suprabasilar vesicles, positive Nikolsky sign, widespread oral blisters) is classic for PEMPHIGUS VULGARIS (PV). In PV: antibodies (IgG) attack desmoglein-1 and desmoglein-3 proteins in desmosomes → suprabasal acantholysis → blisters. Treatment = systemic corticosteroids. Referral to physician/dermatologist is essential. The EXCEPTION is: 'definitive diagnosis should include mucous membrane pemphigoid' — PV and MMP are DIFFERENT conditions. MMP is a subepithelial blistering disease (splits at the BASEMENT MEMBRANE), not suprabasilar. PV diagnosis does NOT include MMP.
- A. INCORRECT (IS true). PV is a potentially life-threatening autoimmune disease requiring systemic management — referral to a physician (dermatologist) is essential.
- B. INCORRECT (IS true). Systemic corticosteroids (prednisone) are the first-line treatment for pemphigus vulgaris to suppress the autoimmune attack on desmosomes.
- C. INCORRECT (IS true). In PV, autoantibodies (IgG) target desmogleins in the desmosomes of epithelial cells, causing acantholysis (loss of cell-to-cell adhesion) and suprabasilar blistering.
- D. CORRECT (this is the EXCEPTION — it is FALSE). Pemphigus vulgaris and mucous membrane pemphigoid (MMP) are distinct conditions. PV = suprabasilar split, anti-desmosome antibodies. MMP = sub-epithelial split at basement membrane, anti-hemidesmosome antibodies. Diagnosing PV does NOT include MMP.