Pigmentary disorders: 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 · Pigmentary disorders

Sample item

A woman has symmetrical brown patches over the cheeks and forehead. Under Wood's lamp, which finding indicates that the pigment is mainly epidermal?

ACoral-red fluorescence of the lesionBNo change, or reduced contrast, between the lesion and normal skinCEnhanced contrast between the lesion and normal skinDBright apple-green fluorescence of the lesion

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

The answer and the reasoning

C. Enhanced contrast between the lesion and normal skin

Wood's lamp (about 365 nm) accentuates epidermal pigment so that the lesion looks darker against normal skin. Dermal pigment is not enhanced, and a mixed type shows partial enhancement. This helps predict the response to depigmenting agents.

Option by option

A. Coral-red fluorescence of the lesion
Coral-red fluorescence is seen in erythrasma due to porphyrins from Corynebacterium.
B. No change, or reduced contrast, between the lesion and normal skin
Unchanged or reduced contrast suggests a dermal pigment rather than an epidermal one.
C. Enhanced contrast between the lesion and normal skin (correct)
Correct. Epidermal melanin absorbs the long-wave ultraviolet light and is accentuated.
D. Bright apple-green fluorescence of the lesion
Apple-green fluorescence is seen with some tinea capitis and Pseudomonas infection, not with melasma.

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.

Questions about this Dermatology question

What is the answer to this Dermatology question?

The best answer is C, Enhanced contrast between the lesion and normal skin. Wood's lamp (about 365 nm) accentuates epidermal pigment so that the lesion looks darker against normal skin.

Why is "Coral-red fluorescence of the lesion" not the answer?

Coral-red fluorescence is seen in erythrasma due to porphyrins from Corynebacterium.

Why is "No change, or reduced contrast, between the lesion and normal skin" not the answer?

Unchanged or reduced contrast suggests a dermal pigment rather than an epidermal one.

Why is "Bright apple-green fluorescence of the lesion" not the answer?

Apple-green fluorescence is seen with some tinea capitis and Pseudomonas infection, not with melasma.

What concept does this question test?

It tests Pigmentary disorders in Dermatology. Dermal pigment is not enhanced, and a mixed type shows partial enhancement. This helps predict the response to depigmenting agents.

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 Pigmentary disorders?

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.