A contribution by a fellow (non-infectious diseases) colleague, with an offer of a small prize for one local (i.e. Singapore) medical student who provides the correct answer.

Question: What is the clinical sign demonstrated in the photo and what are possible underlying causes?

[Updated 11th February 2016]

The patient in question had chemotherapy resulting in severe loss of appetite and vomiting for a significant period of time. The image shows the characteristic “half-and-half nails” (or Lindsay’s nails) first described in 1967 in patients with chronic kidney disease. In this case, the healthy part of each nail is the bottom half.

Congratulations to those who got it right. Feel free to email me at: hsuliyang@mac.com with relevant contact details.