What are the dangers of head lice?

People with head lice who scratch their heads run the risk of developing secondary infections that can become quite severe, according to Healthline. Without treatment, head lice, and that same risk of infection, spread to others who come in contact with the patient.

Head lice can only lay eggs and live on the heads of their hosts, notes Healthline. While the itching and scratching are an annoyance, and the infections that develop from scratching with dirty nails are often severe, head lice are not as dangerous as body lice. Because of the relative lack of danger, Healthline reports that such groups as the National Association of School Nurses and the American Academy of Pediatrics recommend allowing children with head lice back into school as soon as treatment begins.