Periungual warts are notoriously hard to treat because the nail protects the virus. Laser is actually a great option for kids because it is bloodless and precise. For a child, the doctor will almost certainly use a topical numbing cream (EMLA) for 45 minutes, plus maybe a local anesthetic injection. The injection is the worst part – but many pediatric dermatologists use a 'freeze spray' to numb the skin before the injection, so the child feels almost nothing. General anesthesia is not needed unless the child is extremely uncooperative or the cluster is huge. The procedure itself takes 5-10 minutes. The laser will kill the wart tissue, which will turn black and fall off over two weeks. It might leave a small divot in the nail, but nails grow out. The risk of damaging the nail matrix with laser is lower than with acid or surgery. Find a pediatric dermatologist who does laser regularly.