Pigmentary & Appendageal MCQs

Dermatology · 6 free questions with answers & explanations.

1. A 30-year-old woman presents with acquired, symmetric, irregular hyperpigmented macules on the cheeks, upper lip, and forehead that worsen in summer and during her pregnancies. She takes oral contraceptive pills. Wood's lamp examination significantly accentuates the pigmentation. What does this Wood's lamp finding suggest about the melanin location, and what is the FIRST-LINE topical treatment?
2. A 25-year-old woman with type IV skin presents with well-defined, chalky-white patches on the dorsa of hands, neck, and perioral area. The patches show complete depigmentation on Wood's lamp with no residual pigment. She has a family history of thyroid disease. Which of the following investigations would be MOST appropriate to screen for associated systemic disease?
3. A 16-year-old boy presents with multiple café-au-lait macules (CALMs), axillary freckling (Crowe's sign), and a soft, flesh-coloured pedunculated nodule on the back. Ophthalmological examination reveals small, pigmented hamartomas on the iris. His father has similar lesions. What is the mutation responsible for this autosomal dominant neurocutaneous syndrome?
4. A 40-year-old woman presents with progressive hair loss forming an inverted triangular area at the frontoparietal hairline, sparing the frontal hairline itself. On trichoscopy, peripilar casts and follicular yellow dots are absent, but perifollicular erythema and scale are present. Biopsy shows a lichenoid infiltrate at the infundibulo-isthmic region with fibrous tracts replacing follicles. What is the diagnosis?
5. A 22-year-old woman presents with comedones, inflammatory papules, pustules, and nodules on her face and upper back. She has a history of regular menstrual irregularities and mild hirsutism. Hormonal work-up shows elevated free testosterone. Which oral agent targets the sebaceous gland most directly by reducing sebum production and is the ONLY drug that addresses all four pathogenic factors of acne?
6. A 65-year-old man presents with a slowly enlarging, dark-brown to black, asymmetric macule on the left cheek with irregular borders and variegated pigmentation. Dermoscopy shows regression structures, atypical pigment network, and grey pepper-like dots. An excision biopsy is performed. Which histopathological finding would indicate the WORST prognosis according to the current AJCC staging system?