SPEX Dermatology 2 ā Questions and Answers
Question 1: Tinea versicolor, characterized by hypo- or hyperpigmented patches, is most commonly caused by which organism?
- Trichophyton rubrum
- Candida albicans
- Malassezia furfur (Correct answer)
- Microsporum canis
Correct answer: Malassezia furfur
Tinea versicolor is caused by Malassezia furfur (Pityrosporum ovale), a commensal yeast that overgrows in warm, humid conditions and disrupts normal skin pigmentation.
Question 2: Wickham striaeāfine white lacy lines on skin lesionsāare pathognomonic for which dermatological condition?
- Psoriasis
- Lichen planus (Correct answer)
- Pityriasis rosea
- Lichen sclerosus
Correct answer: Lichen planus
Wickham striae are fine white lacy lines on lesion surfaces that serve as a characteristic diagnostic feature of lichen planus, a T-cell-mediated inflammatory condition.
Question 3: What is the first-line treatment for uncomplicated scabies in adults?
- Oral ivermectin
- Topical permethrin 5% cream (Correct answer)
- Topical lindane 1%
- Oral doxycycline
Correct answer: Topical permethrin 5% cream
Topical permethrin 5% cream is the first-line treatment for scabies, applied to the entire body from the neck down and left for 8-14 hours; oral ivermectin is an alternative for cases where topical treatment is impractical.
Question 4: Which subtype of melanoma carries the worst prognosis due to its rapid vertical growth phase without a preceding radial growth phase?
- Superficial spreading melanoma
- Lentigo maligna melanoma
- Nodular melanoma (Correct answer)
- Acral lentiginous melanoma
Correct answer: Nodular melanoma
Nodular melanoma has the worst prognosis because it grows vertically from the outset without a radial growth phase, resulting in greater depth of invasion at diagnosis and higher rates of metastasis.
Question 5: In the ABCDE criteria for evaluating suspicious skin lesions for melanoma, what does the 'E' stand for?
- Elevation above surrounding skin
- Evolution or change over time (Correct answer)
- Extent of erythema
- Exudate from the lesion
Correct answer: Evolution or change over time
In the ABCDE criteria (Asymmetry, Border, Color, Diameter, Evolution), 'E' stands for Evolutionāany change in size, shape, color, or symptoms such as bleeding over time.
Question 6: Target (iris) lesions with three concentric zones on the skin and mucous membranes are characteristic of which hypersensitivity reaction?
- Pemphigus vulgaris
- Bullous pemphigoid
- Erythema multiforme (Correct answer)
- Dermatitis herpetiformis
Correct answer: Erythema multiforme
Erythema multiforme is characterized by target or iris lesions with a central dark zone, pale edematous ring, and outer erythematous ring, most commonly triggered by herpes simplex virus.
Question 7: What is the first-line topical treatment for inflammatory rosacea (papules and pustules)?
- Topical tretinoin
- Topical metronidazole (Correct answer)
- Topical hydrocortisone
- Topical salicylic acid
Correct answer: Topical metronidazole
Topical metronidazole is a first-line treatment for inflammatory rosacea, reducing papules and pustules through anti-inflammatory mechanisms; topical azelaic acid is an effective alternative.
SPEX Dermatology 2
Tinea versicolor, characterized by hypo- or hyperpigmented patches, is most commonly caused by which organism?