Differential Diagnosis of Purpura Fulminans
This has come up in Question 14.2 from the second paper of 2010.
The question ("What the hell is this?") was accompanied by an image which resembles the one below:
That is purpura fulminans, resulting - in this case - from menigococcal sepsis.
The image was stolen shamelessly from www.unboundedmedicine.com to replace the college's proprietary purpura picture.
A less florid (and therefore more common) appearance in an asplenic adult can be seen below:
If this ever comes up again, it is likely that the college will expect the candidates to generate a list of differentials to explain this appearance.