No nit and no lice policies are imprudent, as they are based on misinformation, hysteria and intolerance rather than on science. The discovery of lice or their eggs on students should not cause them to miss school.

Exclusionary policies for lice were adopted early in the last century when body lice and infections they transmitted caused global epidemics. More recently, body lice and head lice were recognized as distinct in their biology, epidemiology, medical and public health significance. Body lice can spread disease but are restricted mainly to indigent adults. Head lice, which do not spread disease, are relatively trivial and serve as occasional nuisances that mainly affect young children. They do not cause epidemics.

Exclusionary policies are so entrenched that most folks believe they must be necessary and effective. Inertia is a strong force, and any effort to even suggest changing the policies is met with vigorous resistance by a misinformed, aggressive and highly vocal minority. The result is a political hot potato that causes angst among school administrators. Those who seek to pursue policies based on science and evidence-based practice tend to relent to the intense pressure and venom hurled by dissenting parents. 

Louse exclusion policies are discouraged by the American Academy of Pediatrics, the National Association of School Nurses and by the Centers for Disease Control and Prevention. Many school systems have consequently eliminated or modified their procedures. Instead of the feared epidemics, the change has resulted in relative calm, greater emphasis on education, fewer unnecessary absences and treatments, and cost savings for parents and schools. Kids will continue to have lice regardless of a school's policy, be it no nit, no live lice or one that says "all kids are welcome." 

The New York City Department of Education and Department of Mental Health and Hygiene were leaders in 2007 when they replaced their no-nit policy with a no-live-lice strategy. The next step, allowing children even with live lice to stay in the classroom, is long overdue.