Hair and Nail Disorders MCQs

Dermatology · 19 free questions with answers & explanations.

1. A 28-year-old woman notices diffuse hair shedding 3 months after delivering a baby. Pull test is positive with predominantly telogen hairs. The scalp appears normal. What is the diagnosis?
2. A patient with psoriasis presents with yellow-brown discoloration of the nail plate proximally, with the nail separating from the nail bed distally, and multiple pits on the nail surface. The yellow-brown area has a distinct border. What is the yellow-brown area called?
3. A 28-year-old woman has diffuse hair thinning, predominantly in the crown, 3 months after delivery of her first child. Trichogram shows >25% telogen hairs. The most likely diagnosis and appropriate management are:
4. A patient with psoriasis has nail changes showing oil-drop/salmon patch, onycholysis, and subungual hyperkeratosis. The nail finding most specific to psoriatic nail disease (and correlating most strongly with psoriatic arthritis) is:
5. A 30-year-old woman presents with diffuse hair loss 3 months after childbirth. Pull test is positive with 8 hairs, and the telogen-to-anagen ratio on trichogram is 40:60. The mechanism of this type of hair loss is:
6. Yellow nail syndrome is characterized by the triad of yellow nails, lymphedema, and recurrent pleural effusions/bronchiectasis. The nail finding in yellow nail syndrome that differentiates it from onychomycosis includes:
7. A 28-year-old woman presents with diffuse hair shedding 3 months after delivery of her baby. Trichoscopy shows increased proportion of telogen hairs and short regrowing hairs (upright regrowing hairs). The pathophysiology is:
8. A 30-year-old man presents with patchy hair loss, and trichoscopy reveals 'yellow dots' and 'cadaverized hairs' (black dots). The dermal pathology in alopecia areata is characterised as:
9. A 30-year-old woman with androgenetic alopecia has a Ludwig grade II pattern. Treatment with 5% minoxidil topical solution shows partial response. She inquires about oral finasteride. Which enzyme does finasteride inhibit, and what is its specific isoenzyme selectivity?
10. A patient presents with onycholysis, subungual hyperkeratosis, and dystrophic changes of all 20 nails since childhood. Histopathology shows spongiosis and parakeratosis of the nail bed. The diagnosis is twenty-nail dystrophy (trachyonychia). Its most common association is:
11. A 30-year-old woman presents with diffuse non-scarring hair loss 3 months after delivery of her second child. Pull test is positive from multiple sites. Trichoscopy shows increased proportion of telogen hairs (club hairs). The percentage of hairs in telogen that is diagnostic of telogen effluvium on trichoscopy/trichogram is:
12. A patient presents with yellow-brownish thickened nail plates with subungual hyperkeratosis, onycholysis, and an absent lunula. The slow nail growth and lymphedema affecting both lower limbs suggest which syndrome?
13. Frontal fibrosing alopecia (FFA) is a progressive form of primary cicatricial alopecia with characteristic hairline recession. Histologically it resembles:
14. In androgenetic alopecia (AGA) in men, the conversion of testosterone to the active androgen responsible for miniaturisation is catalysed by which enzyme?
15. In alopecia areata (AA), the inflammatory target is the hair bulb in the anagen phase. Which specific immune mechanism is responsible for breaking the immune privilege of the hair follicle?
16. A 28-year-old woman experiences diffuse hair loss 3 months after delivering a baby. The hair loss is non-scarring and diffuse. Trichoscopy shows increased proportion of telogen hairs with empty follicular ostia. The diagnosis is telogen effluvium. Which underlying condition, if present concomitantly, would most commonly perpetuate the hair loss beyond the expected 3–6 month self-limited course?
17. A patient with 40% nail involvement shows pitting, oil-drop (salmon patch) discolouration, onycholysis, and subungual hyperkeratosis of all fingernails. He has plaque psoriasis. The nail finding most specifically associated with psoriatic arthritis (rather than psoriasis alone) is:
18. A 35-year-old woman presents with a 3-month history of diffuse hair loss, 200–300 hairs/day on counting. She had a severe COVID-19 illness 4 months ago. Trichoscopy shows predominance of telogen hairs. The pathophysiology of this condition is:
19. Twenty-nail dystrophy (trachyonychia) in a child is most commonly associated with which dermatological condition?