Pigmentary Disorders (Vitiligo, Melasma) MCQs

Dermatology · 26 free questions with answers & explanations.

1. A 25-year-old woman presents with well-defined chalk-white macules over the face, hands, and genitalia for 2 years. Wood's lamp examination shows brilliant white fluorescence with sharp borders. She has associated hypothyroidism. What is the pathomechanism?
2. A 30-year-old pregnant woman develops symmetric brown hyperpigmentation over the malar cheeks, forehead, and upper lip. The pigmentation is limited to sun-exposed areas and worsened during pregnancy. On Wood's lamp examination the pigmentation is accentuated. Which type of melasma does she have?
3. A 20-year-old man with vitiligo shows segmental distribution following a dermatomal pattern on his trunk, which appeared abruptly and stabilized within 2 years. Koebner's phenomenon is absent. Which type of vitiligo is this?
4. A 35-year-old woman with symmetrical hyperpigmentation of the upper lip, cheeks, and forehead is treated with triple combination cream. Which three agents constitute the most commonly used triple combination for melasma?
5. A patient with vitiligo has depigmented patches on the lips and fingertips. Wood's lamp examination shows bright chalky-white fluorescence. Which treatment modality is specifically indicated for segmental vitiligo that is stable for more than 1 year?
6. Vogt-Koyanagi-Harada (VKH) syndrome includes bilateral uveitis, poliosis, and vitiligo-like depigmentation. The autoimmune target responsible for these manifestations is:
7. In melasma, which of the following dermal changes distinguishes the dermal type from the epidermal type on Wood's lamp examination?
8. A 35-year-old woman with vitiligo is evaluated for surgical candidacy. She has had stable patches for 2 years, no new lesions, and positive Koebner's phenomenon currently. What is her surgical suitability status?
9. On Wood's lamp examination of vitiligo lesions, the depigmented patches appear chalk-white and enhance. This is due to:
10. Melasma is classified by Wood's lamp examination into epidermal, dermal, and mixed types. Dermal melasma appears darker on Wood's lamp compared to surrounding skin: True or False? And which type responds BEST to topical treatment?
11. A patient with active vitiligo has autoantibodies detected in her serum. The primary mechanism of melanocyte destruction in vitiligo is best characterized by:
12. For repigmentation in localized, stable vitiligo unresponsive to medical therapy, the most effective surgical technique that yields the best colour match is:
13. A 35-year-old woman presents with symmetrical hyperpigmentation of the cheeks, upper lip, and forehead. Wood's lamp examination shows marked enhancement of pigmentation. This indicates that the melanin is predominantly located in the:
14. A 22-year-old woman with stable non-segmental vitiligo for 2 years is seeking surgical treatment. She has 5% total body surface area affected. The gold standard surgical procedure offering the best color match for vitiligo is:
15. A patient with melasma has tried topical hydroquinone 4% for 3 months with inadequate response. Histopathology of melasma skin shows increased melanin in both epidermis and dermis with occasional melanophages. This pattern is called:
16. In non-segmental vitiligo, the autoimmune hypothesis implicates cytotoxic CD8+ T cells targeting melanocytes. A serum biomarker that reflects melanocyte destruction and correlates with disease activity is:
17. The Koebner phenomenon (isomorphic response) is seen in vitiligo. Which type of vitiligo does NOT show Koebnerisation?
18. A patient with segmental vitiligo involving the face and neck enquires about surgical treatment. Which procedure is most appropriate for stable segmental vitiligo (inactive for >1 year) with small lesion area?
19. Melasma refractory to topical triple combination (hydroquinone + tretinoin + steroid) is treated with a chemical peel. Which peeling agent is preferred for darker skin types (Fitzpatrick IV–V) to minimise post-inflammatory hyperpigmentation risk?
20. In non-segmental vitiligo, the autoimmune destruction of melanocytes is primarily mediated by:
21. The Wood's lamp (365 nm UVA) examination in melasma shows enhanced contrast of pigmentation under the lamp compared to visible light. This 'Wood's lamp-accentuated' pattern indicates pigment is located in:
22. A dermatologist treating segmental vitiligo recommends melanocyte-keratinocyte transplantation procedure (MKTP). This surgical technique is best suited when:
23. Melasma pathogenesis involves which interaction that drives epidermal hyperpigmentation beyond simple sun exposure?
24. A 30-year-old woman with vitiligo of 2-year duration is being considered for autologous non-cultured epidermal cell suspension transplantation (ReCell technique). Which criterion must be satisfied before proceeding with this surgical treatment?
25. A 40-year-old woman presents with symmetrical, light-brown malar hyperpigmentation worse in summer and improved in winter. She is on oral contraceptive pills. Dermatoscopy shows a pigment network in the epidermis. Wood's lamp examination shows enhancement of the lesion. The most appropriate first-line topical treatment is:
26. A vitiligo patient is found to have segmental vitiligo on the left cheek corresponding to the V2 dermatome. The clinical significance of segmental vitiligo compared to non-segmental vitiligo includes all of the following EXCEPT: