There are a few symptoms to watch for if you think your tongue may be infected from a piercing. There may be swelling, redness, or pain around the area. If you notice discharge, that’s a big sign that infection is present. Nausea, vomiting, and fever, are signs too, so watch for those.
how to treat tongue piercing infections? – http://www.ehow.com/how_2321446_treat-tongue-piercing-infections.html