Scars on hand and arm from abscess . Any suggestions to treat them? (Photo)

Got clean from IV drug use year ago but had horrible infections on hand and arms. They almost look like cigar burns and they were very deep. Now they look purple tinted. Some are pink. I am willing to do whatever it takes to make them better. I saw a dermatologist and she said laser therapy may help but wants me to see plastic surgeon. Any suggestions?