Do you have a chance? Yes.
A sure thing? No.
Your board score should keep you from getting screened out at derm programs, but no honors in clinicals will hurt some. If you have elective and/or research time, use it to do what you can in derm and try to get good derm letters, of course. Do an away rotation at a place you think you might want to be, but stay away from the "tippity top" programs (NYU, UCSF, Yale, Harvard to name a few), since they have a TON of rotators and that makes it hard to stand out. Try mid-tier programs in places you'd like to be. The top programs are going to take the people with the best numbers regardless of who rotates, IMHO, but the others may be inclined to dish out interviews to rotators.
Apply almost everywhere. You HAVE to be willing to go anywhere.
If you apply, get a ton of interviews, and match, good job. If you apply and aren't getting a lot of interviews, consider dropping out of the match and staying for a 5th year, if your school offers that option. If not, do prelim and then shoot for a derm research fellowship. That makes you much more attractive for "out-of-the-match" spots which creep up from time to time.
If you really want it, there is a way - trust me.