This study will determine efficacy of a new and combined treatment of laryngeal recurrent respiratory papillomatosis (RRP), by using a 585 nm pulsed dye laser (PDL) and a dietary supplement, diindolylmethane (DIM). We will compare this new treatment with PDL-only, in a total of 30 children (15 of each treatment), to determine whether this combined treatment would be effective and safe in preventing the RRP recurrence. This is the first study to combine PDL technique with DIM, to develop a new, voice-preserving and long-term effective method of managing laryngeal RRP in children.