Infections: bacterial, viral, fungal, parasitic: nodular scabies: 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 · Infections: bacterial, viral, fungal, parasitic: nodular scabies

Sample item

Eight weeks after completing permethrin for scabies, a man still has intensely itchy firm red-brown nodules on the scrotum and in the axillae. Skin scrapings show no mites. What is the best explanation and management?

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

The answer and the reasoning

A. Persisting hypersensitivity to mite antigen, treated with a potent or intralesional steroid

Nodular scabies is a delayed hypersensitivity response to retained dead mites and their products, favouring covered sites such as genitalia and axillae. It can persist for weeks to months after cure, so a potent topical or intralesional corticosteroid is used rather than more scabicide.

Option by option

  • A. Persisting hypersensitivity to mite antigen, treated with a potent or intralesional steroid (correct)

    Correct. The nodules reflect an immune reaction to mite remnants and respond to corticosteroids.

  • B. Resistant mites, treated by repeating the scabicide course

    Repeating scabicides is unnecessary when scrapings are negative and the mite has been cleared.

  • C. Secondary syphilis, treated with benzathine penicillin

    Secondary syphilis gives a non-itchy rash with palm and sole involvement and positive serology, and does not explain nodules after treated scabies.

  • D. Cutaneous lymphoma, treated by wide excision

    Lymphoma is rare and would not be assumed in a post-scabies nodule without biopsy evidence.

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.

More Dermatology questions

Questions about this Dermatology question

What is the answer to this Dermatology question?

The best answer is A, Persisting hypersensitivity to mite antigen, treated with a potent or intralesional steroid. Nodular scabies is a delayed hypersensitivity response to retained dead mites and their products, favouring covered sites such as genitalia and axillae.

Why is "Resistant mites, treated by repeating the scabicide course" not the answer?

Repeating scabicides is unnecessary when scrapings are negative and the mite has been cleared.

Why is "Secondary syphilis, treated with benzathine penicillin" not the answer?

Secondary syphilis gives a non-itchy rash with palm and sole involvement and positive serology, and does not explain nodules after treated scabies.

Why is "Cutaneous lymphoma, treated by wide excision" not the answer?

Lymphoma is rare and would not be assumed in a post-scabies nodule without biopsy evidence.

What concept does this question test?

It tests Infections: bacterial, viral, fungal, parasitic: nodular scabies in Dermatology. It can persist for weeks to months after cure, so a potent topical or intralesional corticosteroid is used rather than more scabicide.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Infections: bacterial, viral, fungal, parasitic: nodular scabies?

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.