Alright, so I may have used my vaccume to clean it ... I couldn't find anything to blow the dust out so I just gave it a quick suck.
You just broke rule #1 of cleaning a PC, never use suction! Even though many new PCs don't have as many jumpers some still have them on the motheboard and GFX cards. If you've removed one, you'll never be able to find out where it came from or how it was positioned. Suction can also loosen contacts and cables. You must always use air blowing out. A hair dryer is not a bad option, just make sure it's on the coldest setting and that you don't get it too close to the dust. And yes, that dust may contain large amounts of allergens and you should clean your case outside or while wearing a facemask. Also grounding your PC is never a bad idea.