If you don't think the jewelry is the cause, Nose Rings
then the source of the infection is probably bacterial. The way to fix that is to kill and/or clear the bacteria. The best way to do that is to start cleaning it twice a day and doing sea salt soaks twice a day; TRAGUS Earrings
basically treating it like a brand new piercing. The heat and the salt both help to draw out pus and other fluids that may contain bacteria. Hopefully, following that regimen for a few days will clear up an infection in its early stages.
Full blown infections, however, can lead to other serious problems, so if you are oozing thick or green pus, or if the area is seriously swollen and hot to the touch, you should not attempt to clear the infection on your own. Body piercing trends
You need antibiotics to kill an advanced infection, so please see your doctor.