That reminds me of the joke:
"Derm residency in 10 seconds:
If it's wet, dry it. If it's dry, wet it.
If they're on steroids, stop them. If they're not, start them.
When in doubt, biopsy."
That CNN article says that the ABD exam has a store of 300 questions that are used. Really? My EM written had 330 questions, and those are rotated all around (which, for reasons I shall not elucidate, I know occurs). And, considering all the weird rashes I see in the ED, I would guess without knowing that there could be 1000 or more regular questions.
Contrast that with the 60K questions USMLE says they have in the repository for step I - or, at least, when I took it 12 years ago, it was 60K. Maybe 75K questions now?