IMresident, the funding is different for dermatology if you are a DO or MD. Allopathic-trained physicians seem to have a harder time being accepted when they have completed another residency due to Medicare funding. It seems DO residencies actually value someone who has completed more training--I am not a DO so I do not know much about this route. This is just my observation.
That being said, there is a chance for both allopathic and osteopathic routes. You still need high board scores/class rank for either. If you are an M.D., you could call some of the large programs, like Emory and Mayo, b/c they are not so reliant on MC funding (at least a few years ago).
You can also check "dermboard". There are often suggestions about how to obtain a residency, such as doing a research fellowship. Again, you would want to have high scores, etc before you take a fellowship; otherwise, you may be doing grunt work for 2 years while you continuously get passed over.
Anyways, good luck.