My vote is for the Christmas Tree. New to the house and can carry allergens. Would think it is unlikely that the vacuum dust would still be causing problems.

Another possibility could be the "bucket" theory. Too many allergens attacking your body at the same time and putting your immune system on overdrive.

I would try to isolate one change at a time and see if you can feel a better response.

When my child was allergic to Mucinex, her hives kept randomly popping up for about a week. The nurse at the ped said an allergic reaction can keep your immune system in overdrive for a while.

Get some saline spray for like $2 at CVS and rinse out your nose. Since the windows aren't open this time of year, there may be lingering dust or allergens in your place. That said, it may just be a cold.

Take an antihistimine like benadryl tonight before you go to bed, that may help as well.

I spent quite a bit of time dealing with a clogged vacuum on Sunday and I was covered in dust (I'm allergic to dust/dust mites). I was stuffy the rest of the day, even after a shower, and have been off and on ever since. It clears up when I leave our apartment, so I'm pretty sure it's something here.

We also got a live Christmas tree on Thursday, so it could be that. I read online that they can carry grass and ragweed pollen, or mold spores (another BIG allergy of mine).

Also got the down comforter out a week ago. The first time I used one was last year, but I don't remember having any allergic reactions to it.

I really have no idea where to begin. The symptoms come and go. Could the symptoms be remnants of the episode with the vacuum on Sunday?