Fungal infections: tinea capitis: 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 · Fungal infections: tinea capitis

Sample item

A child has patchy alopecia with broken hairs seen as black dots on the scalp, with scaling. Trichophyton tonsurans is isolated. What is the pattern of hair invasion?

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

The answer and the reasoning

A. Endothrix

In endothrix infection, arthroconidia fill the hair shaft and the hair breaks at the surface leaving black dots. Trichophyton tonsurans and T. violaceum are the usual endothrix species, and oral griseofulvin or terbinafine is needed.

Option by option

  • A. Endothrix (correct)

    Correct. Spores inside the shaft cause black dot ringworm.

  • B. Favus

    Favus is caused by T. schoenleinii with scutula, not black dots.

  • C. Ectoendothrix with fluorescence

    Ectoendothrix does not describe this presentation.

  • D. Ectothrix

    Ectothrix spores lie outside the shaft, as in Microsporum infections.

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, Endothrix. In endothrix infection, arthroconidia fill the hair shaft and the hair breaks at the surface leaving black dots.

Why is "Favus" not the answer?

Favus is caused by T. schoenleinii with scutula, not black dots.

Why is "Ectoendothrix with fluorescence" not the answer?

Ectoendothrix does not describe this presentation.

Why is "Ectothrix" not the answer?

Ectothrix spores lie outside the shaft, as in Microsporum infections.

What concept does this question test?

It tests Fungal infections: tinea capitis in Dermatology. Trichophyton tonsurans and T. violaceum are the usual endothrix species, and oral griseofulvin or terbinafine is needed.

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 Fungal infections: tinea capitis?

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.