Bacterial infections: toxic shock syndrome: 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 · Bacterial infections: toxic shock syndrome

Sample item

A young woman using a tampon has fever, hypotension, diffuse macular erythroderma and later desquamation of the palms and soles. What is the pathogenic mechanism?

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

The answer and the reasoning

D. Superantigen TSST-1 causing massive polyclonal T-cell activation

Toxic shock syndrome toxin-1 of Staphylococcus aureus acts as a superantigen, binding MHC class II and the T-cell receptor outside the usual groove. The cytokine surge causes shock, rash and later peeling.

Option by option

  • A. Immune complex deposition in vessels

    Immune complex vasculitis causes palpable purpura.

  • B. IgE mediated mast cell degranulation

    IgE mediated degranulation causes urticaria and anaphylaxis.

  • C. Direct bacterial invasion of the dermis

    Bacteraemia is usually absent; the toxin rather than invasion is the cause.

  • D. Superantigen TSST-1 causing massive polyclonal T-cell activation (correct)

    Correct. Superantigen-driven cytokine release explains the shock.

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.

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Questions about this Dermatology question

What is the answer to this Dermatology question?

The best answer is D, Superantigen TSST-1 causing massive polyclonal T-cell activation. Toxic shock syndrome toxin-1 of Staphylococcus aureus acts as a superantigen, binding MHC class II and the T-cell receptor outside the usual groove.

Why is "Immune complex deposition in vessels" not the answer?

Immune complex vasculitis causes palpable purpura.

Why is "IgE mediated mast cell degranulation" not the answer?

IgE mediated degranulation causes urticaria and anaphylaxis.

Why is "Direct bacterial invasion of the dermis" not the answer?

Bacteraemia is usually absent; the toxin rather than invasion is the cause.

What concept does this question test?

It tests Bacterial infections: toxic shock syndrome in Dermatology. The cytokine surge causes shock, rash and later peeling.

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 Bacterial infections: toxic shock syndrome?

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.