ABD General MCQ 3

Question 1

Which dermatophyte finding on KOH prep confirms a diagnosis of tinea?

Accepted Answer

Septate branching hyphae

Answer

Dermatophyte infections show septate, branching hyphae on KOH microscopy.

Question 2

The 'spaghetti and meatballs' appearance on KOH is characteristic of which organism?

Accepted Answer

Malassezia furfur

Answer

Malassezia furfur, the cause of tinea versicolor, produces the short hyphae and round spores described as spaghetti and meatballs.

Question 3

Which cutaneous finding is a recognized marker of internal malignancy?

Accepted Answer

Acanthosis nigricans

Answer

Sudden, widespread acanthosis nigricans can be a paraneoplastic sign, classically of gastric adenocarcinoma.

Question 4

A dermatologist notes Wickham striae on violaceous, flat-topped papules on the wrists. What is the diagnosis?

Accepted Answer

Lichen planus

Answer

Purple, polygonal, pruritic, planar papules with fine white reticular Wickham striae are diagnostic of lichen planus.

Question 5

Which layer of the epidermis is absent in thin skin but present in thick skin such as the palms?

Accepted Answer

Stratum lucidum

Answer

The stratum lucidum is a translucent layer found only in thick, glabrous skin of the palms and soles.

American Board of Dermatology (ABD) Practice Test