I was able to keep the sleeping room of my tent almost entirely dust free last year. It's a bit different than an RV, but hopefully the advice is applicable. We had multiple barriers from the outside world to the room: the door of the tent (covered with a thick fleece sheet clipped to the outside, and always closed when not entering or leaving), and the zippered wall in the middle of the tent (with an extra cotton sheet pinned to it to cover the zipper). All the windows were kept closed with cotton or fleece sheets clipped over the outside of them. We shook off outside, then stripped off all our clothes (to our birthday suits) in the front room of tent after entering, and baby wipes were enough to do a thorough wipe down of all the dust on our bodies. Sometimes we got a head start on the dust by wiping some of it off with the wipes outside the tent as well. Also, we covered the bed with a large sheet whenever we left to stop any lingering dust from ending up on our bed. I don't have a dust allergy however, this was to provide a safe haven should my asthma act up really bad (thank goodness it didn't).
If you own the RV, I suggest finding a way to set up a barrier system like I did using something simple like old bed sheets. Cover windows that may have frames that let in dust, and velcro or somehow attach them to the ceiling to make a cubicle around your doorway to help stop dust when you enter and leave the RV. If you have a mini dustbuster style vacuum cleaner that you can recharge, then that can easily be used to suck up dust, as well as wiping down with wet wipes and/or a swiffer duster. Add extra protection/barriers to your sleeping area, as ultimately that's probably the place you want the least dust to get to. Nothing is fool proof through, so get one of those heavy duty chemical painter's masks (the one's with filter cartridges) to wear should you not be able to fully escape the dust and your allergic reactions