How can i treatment my itchy and swelling taattoo which i have got one year ago?

I have a tattoo on my left arm since one year. i did not have any problem in the starting. One day I added the red color on red color area myself. after this day i m suffering from itchy and swelling problem. i m using a medicine,(antibiotic ointment but its not working properly.so please suggest me what i have to do? i am very scared. Waiting your answer.