ABD Inflammatory Dermatoses 2

Question 1

A biopsy of a psoriatic plaque classically shows regular acanthosis, parakeratosis, and collections of neutrophils within the stratum corneum called what?

Accepted Answer

Munro microabscesses

Answer

Munro microabscesses are neutrophil collections in the parakeratotic stratum corneum characteristic of psoriasis.

Question 2

Which cytokine pathway is the primary target of biologics like ustekinumab used in moderate-to-severe plaque psoriasis?

Accepted Answer

IL-12/IL-23 (p40 subunit)

Answer

Ustekinumab blocks the shared p40 subunit of IL-12 and IL-23, central to psoriatic inflammation.

Question 3

The Auspitz sign, elicited by removing psoriatic scale, represents what pathologic feature?

Accepted Answer

Pinpoint bleeding from dilated dermal papillae capillaries

Answer

Scraping psoriatic scale exposes thinned suprapapillary epidermis over dilated capillaries, producing pinpoint bleeding.

Question 4

A patient develops acute generalized pustular psoriasis (von Zumbusch) after abrupt withdrawal of which medication?

Accepted Answer

Systemic corticosteroids

Answer

Rapid tapering or withdrawal of systemic corticosteroids can precipitate generalized pustular psoriasis.

Question 5

Guttate psoriasis in a child or young adult is most classically triggered by which preceding infection?

Accepted Answer

Streptococcal pharyngitis

Answer

Guttate psoriasis frequently follows a group A streptococcal throat infection.

American Board of Dermatology (ABD) Practice Test

American Board of Dermatology (ABD) Practice Test

ABD Inflammatory Dermatoses 2