Footnotes

• Contributors Both authors reviewed this patient within the ED. Both contributed to the writing of the manuscript.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Provenance and peer review Not commissioned; internally peer reviewed.

• Correction notice Since this image challenge was first published online, a correction has been made to option D in the question section. The abbreviation APL should read abductor pollicis longus and not adductor pollicis longus.