Papulosquamous disorders: habit-tic nail deformity: 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.

Try it

Dermatology · Papulosquamous disorders: habit-tic nail deformity

Sample item

A young man has a longitudinal midline groove in the thumbnail with transverse parallel ridges stacked like a fir tree. He does not have psoriasis or lichen planus. What is the cause?

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

The answer and the reasoning

A. Repetitive picking at the proximal nail fold

Median canaliform dystrophy (habit-tic deformity) results from repeated manipulation of the proximal nail fold. The matrix is traumatised and the nail grows with a central groove and fir-tree ridges, which settle when picking stops.

Option by option

  • A. Repetitive picking at the proximal nail fold (correct)

    Correct. Chronic picking of the nail fold causes habit-tic deformity.

  • B. Matrix damage by lichen planus

    Lichen planus can cause ridging and pterygium and is excluded here.

  • C. Fungal invasion of the nail plate

    Onychomycosis causes yellow thickened crumbly nails, not a midline groove.

  • D. Subungual melanocytic naevus

    A matrix naevus gives a pigmented longitudinal band, not a groove.

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, Repetitive picking at the proximal nail fold. Median canaliform dystrophy (habit-tic deformity) results from repeated manipulation of the proximal nail fold.

Why is "Matrix damage by lichen planus" not the answer?

Lichen planus can cause ridging and pterygium and is excluded here.

Why is "Fungal invasion of the nail plate" not the answer?

Onychomycosis causes yellow thickened crumbly nails, not a midline groove.

Why is "Subungual melanocytic naevus" not the answer?

A matrix naevus gives a pigmented longitudinal band, not a groove.

What concept does this question test?

It tests Papulosquamous disorders: habit-tic nail deformity in Dermatology. The matrix is traumatised and the nail grows with a central groove and fir-tree ridges, which settle when picking stops.

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 Papulosquamous disorders: habit-tic nail deformity?

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.