I have a blood test today, but my top of ear peircing is infected is that going to show on the blood test ?

Depends on what test: If you had a cbc, which includes a white blood cell count (wbc), that may be elevated if you have an active infection going on in your body right now. Better to know and get treated if you do have an infection. If the infection is mild, though, your blood work may be completely normal.

Depends: What tests are you getting done? Some results like white blood cell count and inflammation markers may be elevated. Most others are not likely to affected to a meaningful extent.

Unlikely: Localised cellulitis may not show up in regular cbc. It easily evaluated with need for blood work.

No: Local infections won't change much, usually. It takes a systemic infection to alter your blood parameters.

IT MAY OR MAY NOT: It may show elevated white blood cells or may be normal.But if you see infection, consult yourdoctor as you my need topical orsystemic antibiotics. Options of your treatment do not dependon your white cell count.But if you need to know what bacteria is causing theinfection, ask your doctor to take a culture.