You never really HAVE to state that you're a reapplicant unless you're asked during an interview... And unless you're asked "Have you applied before in the last 3 years?" I don't see how you can get out of answering it honestly. Still, there's nothing wrong with it- taking time off to pursue something else, then coming back shows that you might be more sure that medicine is for you than say, a first time applicant right out of (or still in) undergrad.
Depending on the school's application, you may have to say that you are a reapplicant - look for the check box. AMCAS does bind you to confirming that everything in your application is true to the best of your knowledge, which includes re-applicant status.