Infections: cercarial dermatitis: 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: cercarial dermatitis

Sample item

After wading in a freshwater pond, a boy develops intensely itchy red papules on the exposed legs within hours, resolving in a week. Which organism causes this?

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

The answer and the reasoning

B. Avian schistosome cercariae

Cercarial dermatitis, or swimmer's itch, is a hypersensitivity reaction to penetration by avian or animal schistosome cercariae that cannot mature in humans. It is self-limiting and treated with antihistamines and topical steroids. Creeping eruption has a serpiginous track instead.

Option by option

  • A. Pediculus humanus

    Lice cause itching of the scalp or body folds, not exposure-linked papules.

  • B. Avian schistosome cercariae (correct)

    Correct. Avian schistosome cercariae cause swimmer's itch.

  • C. Sarcoptes scabiei

    Scabies produces burrows and persists untreated.

  • D. Ancylostoma braziliense larvae

    Hookworm larvae cause a migrating serpiginous track.

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 B, Avian schistosome cercariae. Cercarial dermatitis, or swimmer's itch, is a hypersensitivity reaction to penetration by avian or animal schistosome cercariae that cannot mature in humans.

Why is "Pediculus humanus" not the answer?

Lice cause itching of the scalp or body folds, not exposure-linked papules.

Why is "Sarcoptes scabiei" not the answer?

Scabies produces burrows and persists untreated.

Why is "Ancylostoma braziliense larvae" not the answer?

Hookworm larvae cause a migrating serpiginous track.

What concept does this question test?

It tests Infections: cercarial dermatitis in Dermatology. It is self-limiting and treated with antihistamines and topical steroids. Creeping eruption has a serpiginous track instead.

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 Infections: cercarial dermatitis?

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.