Immunopathology: pemphigus vulgaris: practice question

A Pathology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Pathology · Immunopathology: pemphigus vulgaris

Sample item

A 45-year-old woman has flaccid blisters that rupture easily to leave painful erosions in the mouth and skin, and the Nikolsky sign is positive. Direct immunofluorescence of perilesional skin would show which pattern?

AGranular immunoglobulin along the dermo-epidermal junctionBLinear IgG and C3 along the basement membraneCIntercellular IgG deposits in a fishnet patternDGranular IgA in the dermal papillae

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Intercellular IgG deposits in a fishnet pattern

Pemphigus vulgaris is a type II hypersensitivity in which IgG against desmoglein 3 (and 1) causes suprabasal acantholysis. Immunofluorescence shows IgG between keratinocytes in a net-like pattern. Linear basement membrane staining is seen in bullous pemphigoid.

Option by option

A. Granular immunoglobulin along the dermo-epidermal junction
A granular band at the junction is the lupus band of SLE.
B. Linear IgG and C3 along the basement membrane
Linear basement membrane deposits indicate bullous pemphigoid.
C. Intercellular IgG deposits in a fishnet pattern (correct)
Correct. Anti-desmoglein IgG coats the surface of keratinocytes.
D. Granular IgA in the dermal papillae
Granular IgA in the papillae indicates dermatitis herpetiformis.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Pathology question

What is the answer to this Pathology question?

The best answer is C, Intercellular IgG deposits in a fishnet pattern. Pemphigus vulgaris is a type II hypersensitivity in which IgG against desmoglein 3 (and 1) causes suprabasal acantholysis.

Why is "Granular immunoglobulin along the dermo-epidermal junction" not the answer?

A granular band at the junction is the lupus band of SLE.

Why is "Linear IgG and C3 along the basement membrane" not the answer?

Linear basement membrane deposits indicate bullous pemphigoid.

Why is "Granular IgA in the dermal papillae" not the answer?

Granular IgA in the papillae indicates dermatitis herpetiformis.

What concept does this question test?

It tests Immunopathology: pemphigus vulgaris in Pathology. Immunofluorescence shows IgG between keratinocytes in a net-like pattern. Linear basement membrane staining is seen in bullous pemphigoid.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Immunopathology: pemphigus vulgaris?

Learn each disease as a bundle: cause, key histology, markers, and the clinical hallmark. Then use the flashcards and the other Pathology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.