Adhesive Tape Allergy
After a tattoo is applied, it is usually bandaged in one way or another as a part of normal tattoo aftercare. This bandage is usually held on with some form of medical tape. Most people react to some extent to the tape's adhesive and experience minor irritation. However, as you can see from the photo, some people have more extreme allergic reactions — this photo was taken two days after the tattoo was done and the tape was applied.
If you have a major reaction like this, you should probably go and see an allergy specialist. Minor reactions can be minimized by using less sticky tapes and by bandaging carefully to have as little skin contact as possible.