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Onychomycosis — SCE Dermatology MCQ

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

HardNail DisordersOnychomycosisSCE Dermatology

A man has distal-lateral subungual nail dystrophy affecting six toenails and coexistent tinea pedis. Oral terbinafine is being considered. What should be done before the prolonged systemic course?

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

Reveal the answer and explanation

Correct answer: E — Send proximal affected nail material for microscopy and culture while treating the coexistent tinea pedis

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

A is correct. Psoriasis, trauma and other dystrophies can mimic onychomycosis, so an appropriate clipping or subungual sample should confirm fungus before committing the patient to prolonged systemic treatment. Treating coexistent tinea pedis reduces an ongoing reservoir. Clinical appearance alone is insufficient, nail avulsion does not eradicate fungus and is rarely required, skin treatment alone does not reliably cure established nail infection, and corticosteroids can worsen dermatophyte disease.

Reference: BAD fungal nail infections guidance: https://www.bad.org.uk/pils/fungal-nail-infections