Hi I agree with Geminigirl1963,
The WBC count being 12.9 is only slightly raised. You probably have an infection either from the tatoo or sinuses by your description. Sounds like you need antibiotics. I would take another trip to the doctor. Do you have a fever? If you had a disease like leukeumia your WBC count would be 20,000 or higher so I wouldn't worry about that type of thing. The normal range for your WBC count is around 5,000-9,000 or a little higher (depending on the lab that tests it and it's normal range at that lab).
take care and get some rest.
mkh9
An elevated WBC usually indicates an infection somewhere and since you said you've been having sinus issues lately, it's in all likelihood that is the cause for the increase. I would say that if you're not having any signs of infection at the tattoo site - redness, swelling, pain, fever - then that probably is not causing it.
Maybe ask your doc for a round of antibiotics and then after finishing all of them, get another blood test just to see if it has come back down.
I hope you feel better.
do not panic it is not an alarming thing that you'r wbc has raised from normal may be it is suggesting a slight infection and it can be self limited,after 2 weeks repeat total blood count once again to see everything is in normal