I've been having a bit of that and finally figured out it was sinus crud brought on by having to run the furnance full-tilt for weeks and sucking all the humidity out of the house. I have a house bunny who's a Lionhead, and when he was running over the living room carpet this week, his mane was sticking straight out. I laughed and laughed ... then went, "wait." Sure enough, humidity was way low. Not likely to be your problem in WA, though!
~ Becky ~