ABD General MCQ 2 — Questions and Answers
Question 1: A 6-year-old presents with honey-colored crusts around the nose and mouth. What is the most likely diagnosis?
- Impetigo (Correct answer)
- Eczema herpeticum
- Perioral dermatitis
- Tinea faciei
Correct answer: Impetigo
Honey-colored crusting on the face is the classic presentation of non-bullous impetigo, usually caused by Staphylococcus aureus or Streptococcus pyogenes.
Question 2: Which HLA type is most strongly associated with dermatitis herpetiformis?
- HLA-B27
- HLA-DQ2 (Correct answer)
- HLA-B51
- HLA-Cw6
Correct answer: HLA-DQ2
Dermatitis herpetiformis, the cutaneous manifestation of celiac disease, is strongly linked to HLA-DQ2 (and DQ8).
Question 3: A pearly papule with rolled borders and telangiectasias on the nose is most consistent with which tumor?
- Squamous cell carcinoma
- Basal cell carcinoma (Correct answer)
- Keratoacanthoma
- Melanoma
Correct answer: Basal cell carcinoma
A pearly, translucent papule with rolled borders and arborizing telangiectasias is the hallmark of nodular basal cell carcinoma.
Question 4: Nikolsky sign, where the epidermis shears with lateral pressure, is characteristically positive in which condition?
- Bullous pemphigoid
- Pemphigus vulgaris (Correct answer)
- Dermatitis herpetiformis
- Psoriasis
Correct answer: Pemphigus vulgaris
Pemphigus vulgaris involves intraepidermal acantholysis, producing a positive Nikolsky sign, unlike the subepidermal bullous pemphigoid.
Question 5: Which medication is first-line oral therapy for severe nodulocystic acne?
- Doxycycline
- Isotretinoin (Correct answer)
- Spironolactone
- Topical clindamycin
Correct answer: Isotretinoin
Isotretinoin is the most effective agent for severe recalcitrant nodulocystic acne, though it requires pregnancy prevention monitoring.
Question 6: The Auspitz sign (pinpoint bleeding after scale removal) is associated with which disease?
- Lichen planus
- Psoriasis (Correct answer)
- Seborrheic dermatitis
- Pityriasis rosea
Correct answer: Psoriasis
Removing the silvery scale of a psoriatic plaque exposes dilated dermal capillaries, producing pinpoint bleeding known as the Auspitz sign.
Question 7: A patient develops a target-shaped lesion with three concentric zones after a herpes simplex outbreak. What is the diagnosis?
- Erythema multiforme (Correct answer)
- Urticaria
- Fixed drug eruption
- Granuloma annulare
Correct answer: Erythema multiforme
Classic targetoid lesions with three zones following HSV infection are diagnostic of erythema multiforme.
ABD General MCQ 2
A 6-year-old presents with honey-colored crusts around the nose and mouth.
What is the most likely diagnosis?