yeah...it's normal to not have any exposure to derm in the preclinicals...
Though there is a wealth of basic science work going on in derm, in my opinion, it is a very heavily clinical specialty -> you have to see patients with dermatologic concerns, not just read about the conditions. since 1st and 2nd year by it's very nature isn't very clinical, you don't get exposure except to maybe discussions on some of the immune mediated dermatologic conditions, some of the genetic conditions, and some of the childhood exanthems.. It will not hurt you on step 1. And unless you are taking care of patients with acute derm issues, it shouldn't affect you on your rotations.
In terms of getting a derm residency, that's a different beast altogether, and I'll defer discussion of that to some of my derm colleagues.
