When my son came home with a note from the school nurse about possible head lice, we tried all of the traditional home lice remedies, like mayonnaise and tea tree oil shampoos. We also tried to comb out every lice nit we could find. I thought we got ahead of the problem, but he still showed signs of a lice infestation.
That's when my doctor told me about super head lice. He sent us to a special treatment center in another town, and they knew how to treat super lice. This was a serious matter for us, since he wasn't allowed to come back to school until a doctor signed off that the treatment was successful. There were about 5 or 6 children in the same situation as our son, and most of them were out of regular classes for a week.