ABD Inflammatory Dermatoses 2 — Questions and Answers
Question 1: A biopsy of a psoriatic plaque classically shows regular acanthosis, parakeratosis, and collections of neutrophils within the stratum corneum called what?
- Munro microabscesses (Correct answer)
- Pautrier microabscesses
- Civatte bodies
- Kamino bodies
Correct answer: Munro microabscesses
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?
- IL-12/IL-23 (p40 subunit) (Correct answer)
- IL-4/IL-13
- IgE-mediated
- TGF-beta
Correct answer: IL-12/IL-23 (p40 subunit)
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?
- Pinpoint bleeding from dilated dermal papillae capillaries (Correct answer)
- Wickham striae
- Nikolsky separation
- Darier-positive urtication
Correct answer: Pinpoint bleeding from dilated dermal papillae capillaries
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?
- Systemic corticosteroids (Correct answer)
- Topical emollients
- Antihistamines
- Oral vitamin D
Correct answer: Systemic corticosteroids
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?
- Streptococcal pharyngitis (Correct answer)
- Herpes simplex
- Molluscum contagiosum
- Candida intertrigo
Correct answer: Streptococcal pharyngitis
Guttate psoriasis frequently follows a group A streptococcal throat infection.
Question 6: Nail pitting, oil-drop discoloration, and onycholysis in a psoriasis patient raise concern for which associated condition?
- Psoriatic arthritis (Correct answer)
- Contact dermatitis
- Tinea unguium only
- Lichen striatus
Correct answer: Psoriatic arthritis
Nail involvement in psoriasis correlates strongly with concurrent or future psoriatic arthritis.
Question 7: The Koebner phenomenon in psoriasis refers to what?
- New lesions appearing at sites of skin trauma (Correct answer)
- Central clearing of plaques
- Photosensitive facial rash
- Spontaneous blistering
Correct answer: New lesions appearing at sites of skin trauma
Koebnerization is the development of psoriatic lesions at sites of injury such as scratches or surgical scars.
ABD Inflammatory Dermatoses 2
A biopsy of a psoriatic plaque classically shows regular acanthosis, parakeratosis, and collections of neutrophils within the stratum corneum called what?