Well skindoc knows much more than me in regards to derm. (I am a lowly 4th year medical student not even applying to derm). I thought Id give you an opinion.
You are in a big hole because of your scores. I dont know if you are amg or fmg (if you are an fmg, you are in a deeper hole). If there is nothing else you are willing to do other than derm, and you want "to go for derm" then you will prob have to spend 1 or more years after your IM residency doing derm research. You should be in a top IM program and you have to be the most stellar resident. Derm is tough as hell to get into. I would recommend you target an institution you have a reasonable chance in getting into (which is none (sorry to be mean but lets be realistic, if theres a derm residency in your institution, I would focus on that first). Focus on one program...you may have to do research there for a few years. If you do choose to do research, PUBLISH, PUBLISH and PUBLISH. Get to know ppl in the department. Hell do research with the chairman or the PD. Work in their lab. Do not work in any other lab except for these two ppl, and PUBLISH. Since research is mostly conducted at University Hospitals, you will have to do research there, which I would think would be more competitive for community programs. Thus, you will be competing against stellar applicants from across the country!!!!!! Invite the PD/Chairman over to your house. Get to know them as people. If you show them you are genuinely interested, and you work hard and you really busted your arse for them doing research or whatever it takes, you are in.
Well these are my opinions and take it as that. Again, I am not applying for derm, but I thought Id lend you some advice. Dont mean to sound mean, but you have to be realistic. You dont want to be busting your arse for years only later to find out you still cant get in. With the time you wasted doing research or whatever, you could be practicing and making some money.
Good luck in whatever you do.