I have to agree with Atlanta, older and wiser me just stays home. Doesn't make the boss happy but it won't make him happy either when things get worse and I have to be hospitalized. Yes, when I was younger I felt the company would fall apart if I was out 1 day. I remember going into work with a raging bladder infection, so bad I could barely walk. I finally went to the doctor and had to be hospitalized because my temperature was through the roof. Amazingly the office still managed to stay afloat with me gone two whole days.
If you really, really can't take a little time off, then I would do as Atlanta suggests and take OTC meds and try to rest as much as possible when you get home. Also, take a can of Lysol with you and spray everything down for your co-workers' sake. Last thing you want is an office epidemic.
Hope you feel better soon.
