Dermatologist Certificate Trivia 3

Question 1

What term describes the genetic skin disorder characterized by absent or reduced melanin production due to tyrosinase deficiency?

Accepted Answer

Oculocutaneous albinism

Answer

Oculocutaneous albinism results from mutations in genes such as TYR (tyrosinase), leading to absent or severely reduced melanin in skin, hair, and eyes.

Question 2

The phrase 'herald patch' is the classic initial presentation of which common self-limited skin eruption?

Accepted Answer

Pityriasis rosea

Answer

Pityriasis rosea classically begins with a single large 'herald patch' followed days to weeks later by a widespread Christmas-tree pattern eruption.

Question 3

Which vitamin, when severely deficient, causes pellagra with its classic triad of dermatitis, diarrhea, and dementia?

Accepted Answer

Niacin (B3)

Answer

Pellagra results from niacin (vitamin B3) or tryptophan deficiency; the skin shows a photosensitive dermatitis in sun-exposed areas called casal necklace.

Question 4

Which skin sign—yellowing of the sclerae and skin—most commonly indicates which underlying metabolic process?

Accepted Answer

Elevated serum bilirubin from hepatic or hemolytic disease

Answer

True jaundice with scleral icterus reflects hyperbilirubinemia (>2–3 mg/dL) from liver disease or hemolysis, not dietary carotenoids.

Question 5

The Darier sign, elicited by stroking a lesion causing it to urticate and become raised, is pathognomonic for which condition?

Accepted Answer

Mastocytosis (urticaria pigmentosa)

Answer

Darier sign reflects mast cell degranulation in urticaria pigmentosa (cutaneous mastocytosis) upon physical stroking of the lesion.

Dermatologist Certificate Practice Test

Dermatologist Certificate Practice Test

Dermatologist Certificate Trivia 3