Pathology · single question
The BEST clinical test to differentiate mucous membrane pemphigoid from pemphigus vulgaris is:
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Correct answer: A. Nikolsky sign
- A. Correct (as noted by source). The Nikolsky sign (lateral pressure on perilesional mucosa produces new blister formation) is positive in pemphigus vulgaris and may be positive or negative in MMP. The source identified this as the answer for differentiating the two clinically.
- B. Tzanck smear identifies acantholytic cells in pemphigus but cannot differentiate it from MMP.
- C. Culture is for infectious conditions, not autoimmune bullous diseases.
- D. Direct immunofluorescence is the gold standard for definitive diagnosis, showing IgG antibodies intercellularly (PV) vs. IgG/IgA at the basement membrane zone (MMP), but requires biopsy.