Bullous disorders: practice question

A Dermatology 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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Dermatology · Bullous disorders

Sample item

A young man has intensely itchy, grouped vesicles and excoriations over the elbows, knees and buttocks, and he also has gluten-sensitive enteropathy. What would direct immunofluorescence of perilesional skin show?

ALinear IgA along the basement membrane zoneBLinear IgG and C3 along the basement membrane zoneCIntercellular IgG in a net-like pattern within the epidermisDGranular IgA deposits at the tips of the dermal papillae

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

The answer and the reasoning

D. Granular IgA deposits at the tips of the dermal papillae

Dermatitis herpetiformis is the cutaneous expression of coeliac disease. Granular IgA in the dermal papillary tips is diagnostic, and treatment is dapsone with a gluten-free diet.

Option by option

A. Linear IgA along the basement membrane zone
Linear IgA along the basement membrane zone is seen in linear IgA bullous dermatosis, a different disease.
B. Linear IgG and C3 along the basement membrane zone
Linear IgG and C3 along the basement membrane zone is the pattern of bullous pemphigoid.
C. Intercellular IgG in a net-like pattern within the epidermis
Net-like intercellular IgG is the pattern of pemphigus.
D. Granular IgA deposits at the tips of the dermal papillae (correct)
Correct. Granular papillary IgA is the diagnostic immunofluorescence pattern.

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 Dermatology question

What is the answer to this Dermatology question?

The best answer is D, Granular IgA deposits at the tips of the dermal papillae. Dermatitis herpetiformis is the cutaneous expression of coeliac disease.

Why is "Linear IgA along the basement membrane zone" not the answer?

Linear IgA along the basement membrane zone is seen in linear IgA bullous dermatosis, a different disease.

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

Linear IgG and C3 along the basement membrane zone is the pattern of bullous pemphigoid.

Why is "Intercellular IgG in a net-like pattern within the epidermis" not the answer?

Net-like intercellular IgG is the pattern of pemphigus.

What concept does this question test?

It tests Bullous disorders in Dermatology. Granular IgA in the dermal papillary tips is diagnostic, and treatment is dapsone with a gluten-free diet.

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 Bullous disorders?

Learn each condition by its primary lesion, site and signature sign. Then use the flashcards and the other Dermatology 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.