skip to main content

Beau Lines — SCE Dermatology MCQ

Instant feedback + full explanation. One question, done properly.

HardNail DisordersBeau LinesSCE Dermatology

Three months after prolonged intensive-care admission for pneumococcal sepsis, a man develops matching transverse depressions across several fingernails. There is no periungual inflammation. Which anatomical event produced the grooves?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Synchronous temporary interruption of proximal nail-matrix growth

Explanation lettering: B = shown as A · E = shown as B · A = shown as E

E is correct. Beau lines record a temporary interruption of nail production in the proximal matrix. A major systemic insult can arrest several matrices synchronously; subsequent growth carries the depressed segment distally, so its distance from the fold can approximate the timing of illness. Distal onycholysis follows separation at the nail bed or hyponychium, matrix lichen planus produces longitudinal ridging, thinning or pterygium, onychomycosis causes discolouration and subungual debris, and nail-bed psoriasis causes oil-drop change, onycholysis or hyperkeratosis. Multiple aligned grooves after critical illness therefore localise the event to transient matrix growth arrest rather than local nail disease.

Reference: DermNet nail terminology: https://dermnetnz.org/topics/nail-terminology