ABD ABD Hair and Nail Disorders

Question 1

What is the most common cause of diffuse hair loss in adult women in the US?

Accepted Answer

Female pattern hair loss (androgenetic alopecia)

Answer

Female pattern hair loss (androgenetic alopecia) is the most common cause of hair loss in adult women, affecting up to 40% by age 50.

Question 2

Which dermoscopic finding is pathognomonic for alopecia areata?

Accepted Answer

Black dots (cadaverized hairs)

Answer

Black dots (cadaverized hairs), exclamation mark hairs, and yellow dots are all characteristic dermoscopic features of alopecia areata.

Question 3

Onychomycosis is most commonly caused by which organism in the United States?

Accepted Answer

Trichophyton rubrum

Answer

Trichophyton rubrum accounts for approximately 70-80% of onychomycosis cases in the US and is the predominant causative dermatophyte.

Question 4

Nail pitting is a manifestation of psoriasis affecting which part of the nail unit?

Accepted Answer

Nail matrix

Answer

Nail pitting results from focal parakeratosis in the proximal nail matrix that sloughs off, leaving small depressions on the nail surface.

Question 5

Yellow nail syndrome is classically defined by which triad?

Accepted Answer

Yellow nails, lymphedema, and pleural effusions

Answer

Yellow nail syndrome is characterized by slow-growing yellow nails with onycholysis, lymphedema, and pleural effusions or other respiratory manifestations.

American Board of Dermatology (ABD) Practice Test

American Board of Dermatology (ABD) Practice Test

ABD ABD Hair and Nail Disorders