Head lice are commonly seen. You can read about them on Dermnet.
Pediatrician, Melanie Austin has a non-toxic over the counter approach for head lice. It's time intensive but spares your child or you exposure to toxic chemicals.
You can access her protocol at: Download doc_austin_lice.pdf
The standard therapies, are fine, too. This is attached because many people prefer therapies that are less toxic.