I fall down my bike and my arm got hurt.it was about to gt infected but itook an antibiotic.however there is still a big mark on myarm so wht can ido?

Clarify : Never let a small cut in the skin fool you. It is not unusual to see severe infections which came on after a small cut requiring surgery and long term antibiotic therapy. If the swelling, redness and pain at the site of the cut is worsening, seek immediate medical attention. Often a stronger antibiotic is needed. A tetanus shot may also be needed depending on your immunization status.