So, what are you bringing to the office Christmas party? :-)

It's hard to get back in the swing of things when one has been out even without having a problem about which one doesn't wish to share. But I'd feel like I was playing "Who Wants to Be a Millionaire" and had used up one of my crucial lifelines with the "cold" excuse? Can't use that one again for 6 months or so? I would say something like "personal business I had to take care of" and then people are "afraid" to pry :-) Or even, "personal medical problems" and I think as long as you put the "personal" in there, few are going to be brave enough to question further. If they do, just go off on them LOL.