I'd ease into it, man. If I miss time at the gym, my first session back is usually fairly relaxed. Moderate to high reps to get your connective tissues revved back up and maybe some cardio if you feel up to it.
Don't be that sick guy in the gym, though. If you need a few more days rest its not going to hurt your physique. Sure, you'll look flat because the carbs aren't there and the volume is gone, but give it a few days and you'll be right back in business.